FIRE CONTROLMAN VOLUME 5--DISPLAY SYSTEMS AND DEVICES

CATHODE-RAY TUBES Most display devices currently in use employ a cathode-ray tube (CRT) for the display screen. The following information is a review of the fictions and operation of CRTs. ELEMENTS OF A CRT The CRT is a large glass envelope that contains three basic elements: an electron gun, a deflection system, and a phosphor screen. These elements convert electronic signals into visual displays. In our discussion of CRTs, we will first cover monochrome CRTs then we cover color CRTs. All the air in the glass tube must be evacuated to form a vacuum. This is necessary for three reasons: Air molecules disrupt the electron beam as it travels from the anode to the cathode, Gases tend to ionize when subjected to high voltages and are conductive, which would short out the CRT, and Oxygen in the CRT would cause the filament to burn up. Figure 1-1 shows the three basic components: the phosphor screen, the electron gun, and a deflection system. Figure 1-1.–A cathode-ray tube (CRT). 1-2 The Phosphor Screen The inside of the large end, or face, of a CRT is coated with phosphor. Phosphor is a material that displays luminescence when excited by electrons or other sources of radiation. In other words, electrons (beta radiation) striking the phosphor will cause it to glow for a short period of time. The length of time or duration that the display remains on the screen after the phosphor has been hit with electrons is known as persistence. When the electrons are formed into a beam and directed at the phosphor, the beam produces a dot. The intensity, or brightness, of the dot is directly proportional to the intensity of the electron beam. The Electron Gun The electron gun is located in the narrow neck of the CRT. The gun acts as the source of the electron beam. Figure 1-2 illustrates the components of the electron gun. A small ac voltage is applied to the filament to heat the cathode. Heating the cathode causes vast Figure 1-2.–A CRT electron gun. numbers of electrons to be freed from the cathode. When the voltage of the control grid is more positive than the cathode, the beam is turned on, or unblanked, and the electrons are drawn to the anode (phosphor screen). When the control grid is negative with respect to the cathode, the beam is turned off, or blanked. In a monochrome CRT, the beam is either on or off and has a uniform brightness. In a black and white CRT that displays varying shades of gray, the

voltage of the control grid varies to control the strength of the beam. The stronger the beam, the brighter the display is on the phosphor screen. The screen grid voltage remains constant and acts as an accelerator for the beam. A negative charge on the focus grid shapes the electrons into a beam. Varying the charge of the focus grid causes the diameter of the beam to vary to determine optimum focus. Deflection Systems The deflection system in a CRT moves the beams to create the display. Two common types of deflection systems are used in CRTs. These are electromagnetic deflection and electrostatic deflection. ELECTROMAGNETIC DEFLECTION.– Elec- tromagnetic deflection uses a magnetic field generated by four coils to move the beam across the CRT. Electromagnetic deflection is commonly found on CRTs that use a raster-scan type display. Current flows through the electron beam as it moves from the electron gun (cathode) to the phosphor face (anode) of the CRT. This current develops a circular magnetic field. By introducing an external magnetic field, the beam can be deflected. Controlling the polarity and strength of this external field controls the amount and direction of the beam deflection. The magnetic field is introduced into the CRT by the yoke assembly. The yoke consists of four coils of wire mounted at 90-degree increments. The yoke is mounted around the neck of the CRT. Current flowing through the coil produces a magnetic field at a right angle to the coil. The magnetic field will cause the electron beam to deflect. ELECTROSTATIC DEFLECTION CRT’S.– Electrostatic-type deflection CRTs are generally used in radar and oscilloscopes. In the electrostatic deflection CRT, four deflection plates are located inside the CRT. The top and bottom plates control vertical deflection of the beam and the right and left plates control the horizontal deflection of the beam. An electrical charge is applied to these plates to direct the beam to the proper area of the CRT. To move the beam to the right, a positive charge is applied to the right plate to pull the beam while a negative charge is applied to the left plate to push the electron beam to the proper position. The amount of the charge applied to the plates controls the amount of deflection. CRT SCANNING METHODS The creation of a display is known as a scan. Two types of scanning systems are currently in use in CRTs: raster scanning and vector scanning. Raster scan CRTs are commonly used with electromagnetic deflection CRTs. Vector scan CRTs are commonly used with electrostatic deflection systems, although either deflection system can be used with either scanning system. Raster Scanning A raster scan CRT develops the display or picture by painting a series of horizontal lines across the face of the CRT. The electron beam is pulled from left to right. The beam is then turned off and the horizontal deflection voltage returns the beam to the left side, and the vertical deflection voltage pulls the beam down one line space. The left to right motion is the horizontal frequency and is much greater than the top to bottom motion or vertical frequency. The time it takes for the beam to return to the left or top of the screen is known as retrace time. During retrace the beam is blanked. By dividing the horizontal frequency by the vertical frequency, we can determine the maximum number of lines in the raster. Standard television uses 15,750 Hz for the horizontal frequency and 60 Hz for the vertical frequency. Using this formula, we find that the maximum number of lines is 262.5; but some lines are not available because of the time required for vertical retrace. The lines are spaced close enough to each other so the eye cannot detect any variation of intensity. Resolution is the number of lines per inch at the 1-3

Figure 1-3.-Inter1aced scan of a CRT. merge point. Two methods are used to increase the Interlaced scan CRTs are fine for television resolution of CRTs. These are interlaced scan and noninterlaced scan. INTERLACED SCAN.– Interlaced scanning makes it possible to double the number of horizontal lines in a picture. Figure 1-3 illustrates the principle of interlaced scanning in which two scans are required to display the full picture. The odd raster starts in the top left corner of the CRT, while the even raster starts in the top center of the CRT. The two complete scans paint the entire picture. By interlacing the odd and even lines of a picture, resolution can be increased without a noticeable flicker on the screen. Interlaced scanning is used with standard television and some computer monitors. It increases the maximum number of lines per frame to 525. Because of the vertical retrace time, the number of visible lines is 512. 1-4 transmissions and alphanumeric displays, but can cause a visible flicker when displaying fine digital graphics because of the abrupt changes in the levels of intensity required. To solve this problem, most computer monitors use noninterlaced scan. NONINTERLACED SCAN.– Noninterlaced scanning paints the entire frame of data from top to bottom. Figure 1-4 illustrates the noninterlaced scanning method of painting a single frame. To paint an entire frame without a noticeable flicker, the horizontal frequency is increased, which increases the number of lines per frame. The vertical frequency is also decreased from 60 Hz to 50 Hz in most monitors, which further increases the number of lines.

Figure 1-4.—Noninter1aced scan of a CRT. Vector Scan Vector scan CRTs are used extensively in the Data Display Group ANK/UYA-4(V) plan position indicators (PPIs). The circular display screens provide control and display of conventional radar sweep and video data and computer-generated symbology. The CRTs used in the PPIs use electrostatic deflection The methods used to develop the deflection and unblinking signals for radar sweep and video are similar because the same CRT beam is used to develop both presentations. However, the methods used to develop the radar sweep and video are different from the two methods used to develop symbology. In the following paragraphs, you will learn how the X/Y coordinate system is used to position the CRT beam. The X/Y coordinate system uses a grid as a frame of reference. Figure 1-5 illustrates the concept of the X/Y coordinate system. The horizontal line is the X axis, and the vertical line is the Y axis. The intersection of the two lines is the origin of all deflection signals. The origin is normally located at the center of the CRT, but may be offset from the center by operator action. Figure 1-5.—The X/Y coordinate system. The origin is the starting point for measuring along both axes. To the right of the origin, values on the X axis are positive; to the left, values are negative. The values above the origin on the Y axis are positive; below the origin, they are negative. A point anywhere on the screen of the CRT may be defined by two values: an X coordinate and a Y coordinate. The X coordinate is used to develop the horizontal deflection of the CRT beam. A positive X value will move the beam to the right of the origin; a negative X value will move the beam to the left of the origin. Vertical deflection is derived from the Y coordinate value. A positive Y value will deflect the beam upward from the origin, and a negative value will move the beam down. The appropriate X and Y values can be used to position the beam to any point on the CRT. The combination of positive and negative X and Y signals divides the CRT into the four quadrants illustrated in figure 1-5. A third signal is required to control the blanking of the electron beam. The Z (unblank) signal is used 1-5

in the generation of symbology, for sweep retrace, and so forth. We take you through a detailed look at how the vector scan CRT uses these signals to paint the display on the CRT later in this chapter. COLOR CRT’S Thus far our discussion has been about monochrome CRTs. Color CRTs offer a variety of colors and are used extensively with personal computers, simulators, and other training devices. Most color CRTs use a raster-scan type deflection. The major differences between color and monochrome CRTs are in the phosphor coating of the CRT, the electron gun(s), and the high voltage requirements. The phosphor coating of a color CRT is made up of small dots that contain a dye so they radiate one of the three primary colors of light (red, green, or blue). These dots are arranged in groups called triads. Figure 1-6 illustrates a typical grouping of triads. The size of the phosphor dots is often used as a measure of the CRT’s resolution. Newer monitors have CRTs with dots of .20 mm and smaller. The dots are the smallest addressable element of a picture. These picture elements are called pixels or pels, depending on the manufacturer. Both terms have the same meaning. Three electron beams are required to properly strike the different colored phosphor dots. Some color CRTs use three electron guns, known as a delta gun CRT. The beams pass through a shadow mask that is designed so that only the red gun strikes the red dots, the blue gun strikes the blue dots, and the green gun strikes the green dots. Newer color CRTs have combined all three electron beams into a single gun, as shown in figure 1-6. The single-gun CRT does not need convergence alignments and greatly reduces the amount of circuitry required in a color monitor. This design is common in almost all of the newer color monitors. Figure 1-6.—A typical color CRT. 1-6

DISPLAYING RADAR SWEEP, VIDEO, AND SYMBOLS In the following sections, we cover the steps involved in displaying radar sweep, video, and symbols on the PPI used in the Data Display Group AN/UYA-4(V). RADAR SWEEP AND VIDEO The PPI scan or sweep originates in the center of the circular screen. The sweep progresses (traces) outward until the edge of the screen or the end of sweep is reached. One sweep occurs for each radar pulse transmitted. The angle of the sweep varies as the position of the rotating radar antenna varies, resulting in a clockwise or counterclockwise rotation of the sweep on the screen. As the antenna is rotated, the sweep rotates around the CRT in synchronism with the antenna position. The PPI provides real-time range and bearing display of radar, sonar, or IFF/SIF returns. The sweep trace is intensified (brightened) by video signals that indicate the range of the return. The angle of the sweep on the screen indicates the bearing of the return. The PPI console sweep and video display is generated from data received from the radar, sonar, or IFF. Ancillary equipment converts the data into a format that can be used by the PPI console. The PPI console receives the following information from the conversion equipment: Digital sweep (digital ∆Χ/∆Υ pulse trains) Sign of X and sign of Y Sweep timing (end-of-sweep and range-mark signals) Video Digital Sweep The digital sweep pulse trains (∆Χ/∆Υ) are used to control the deflection of the CRT electron beam. 1-7 They indicate the changing sweep coordinates for the display of the rotating sweep. Sign of X and Sign of Y The sign of X and the sign of Y determine the quadrant in which the sweep and video will be displayed. Sweep Timing Sweep timing signals include range-mark signals and the end-of-sweep signal. The zero-mile range mark is used to start the sweep deflection outward from the center of the screen. Other range-mark signals are displayed as intensified rings on the CRT so that a relationship between the radar video and range may be established. The end-of-sweep signal causes the CRT beam to be blanked and retraced to the center of the CRT. The end-of-sweep signal also resets various counters in preparation for the next sweep. Video Radiation reflections from the radar, sonar, or IFF/SIF are received as video signals. The video signals are displayed as an intensification of the sweep. SYMBOL GENERATION The generation of display symbology is integrated with the development of the sweep and video. Symbols are generated from data words outputted by the computer. The following steps are required to paint a symbol: 1. 2. 3. 4. 5. Blank the sweep Move the CRT beam to the symbol coordinates Paint the symbol Blank the CRT beam Move the beam back to sweep position

Figure 1-7.—The AN/UYA-4(V) symbol set. Two different methods of painting symbols are currently in use in the AN/UYA-4(V) display group. They are the analog waveform and the digital stroke methods. The symbols being generated are the same in either case, only the methods used to generate the symbols differ. Figure 1-7 shows the symbol set used in the AN/UYA-4(V) display group. The AN/UYQ-21(V) computer display set has an expanded symbol set and develops sweep and symbols using both the digital stroke method and raster-scan CRTs, depending on the type of console. Figure 1-8 shows the AN/UYQ-21(V) symbol set. Analog Waveform Symbol Generation To help you to fully understand the analog waveform generation process, we look at the equipments required and the procedure that takes place. Analog symbols are formed by applying harmonious waveforms to the deflection plates of a CRT. For example, if two sine waves of equal amplitude and 90-degrees out of phase are applied to the X and Y axes of a CRT, a circle will be displayed on the CRT. By adding the Z, or unblinking signal, we can control what part of the circle is actually displayed and thus form the symbol. Ellipses are formed when the amplitudes of the two sine waves are unequal. Using the same principle with two trapezoid waveforms that are 90-degrees out of phase, a square will be formed. 1-8

Figure 1-8.—The AN-UYQ-21(V) symbol set. Symbols are defined by computer words. The computer, using data input by the operator, determines what symbol to display and where to display it on the X/Y grid. It then puts together a digital message and transmits it to a piece of ancillary display equipment called a pulse amplifier/symbol generator (PA/SG). Figure 1-9 illustrates how the pulse amplifier interfaces the computer with the symbol generator and the display consoles. It amplifies and distributes the computer output data to the symbol generator and the display consoles. The pulse amplifier also receives computer input data from sends it to the computer. When a symbol message is sent to the display equipment, the console takes control of the CRT electron beam from the radar scan logic. It positions the blanked CRT beam to the coordinates of the symbol to be displayed and waits for the symbol waveforms from the symbol generator. The symbol generator develops the symbol waveforms and timing pulses for the mechanization (display) of the symbol. The timing pulses synchronize the console’s painting of the symbol. the display consoles and Each symbol is composed of the following three 1-9

Figure 1-9.—The waveform symbol equipments (PA/SG) interface path, signals: X-axis waveforms, Y-axis waveforms, and Z (unblinking) signals. The symbol is painted in a timing period called P-time. The symbol generator, using a series of P-time interval signals, develops the proper waveforms to be sent to the CRT deflection amplifiers and video amplifiers. When the symbol generator starts its P-time counter, a signal is sent to the display console that starts an identical counter in the console. This ensures that both equipments are synchronized. Figure 1-10 shows the development of a symbol using the X, Y, and Z waveforms. The symbol is formed during the unblanked P-time intervals. The symbol shown in figure 1-10 is actually a combination of three symbols: air unknown, rocker, and full upper bar. The unblank times have been given reference letter designations to aid you in following the mechanization process. During unblank time A, the rocker is formed. Figure 1-11 illustrates this process on an X/Y plot. When the unblank signal is high, the X sine wave is at its negative point and transitions to its positive point. At the same time, the Y waveform is at zero and transitions its negative cycle, and returns to zero. During unblank B, the Y waveform provides the proper position for the upper bar, while the X waveform transitions from negative to positive. The unknown air symbol is formed during unblank time C. Note that with the trapezoid waveform, X remains at a constant negative level, while Y goes from zero to the positive level. This draws the left vertical side of the symbol. When Y reaches its positive level, X starts a transition from negative to positive to draw the top of the symbol. The right side of the symbol is formed when the Y waveform goes in a negative direction to zero, while X remains at a constant positive level. The dot is formed at unblank time D by unblinking X and Y at the zero level. At the completion of the P-time, the console returns control of the CRT beam to the radar scan logic. The symbol remains displayed on the screen as long as the persistence of the screen phosphor permits. For the symbols to remain flicker free, they must be periodically refreshed, or repainted, by repeating the process just described. Symbols are refreshed 15 to 20 times per second. 1-10

Figure 1-10.—Development of an analog waveform symbol. Figure 1-11.—The mechanization of an analog waveform symbol. 1-11

Digital Stroke Symbol Generation The digital stroke method of symbol generation is used in some AN/UYA-4(V) display groups that use the console internally generated and refreshed symbols (CIGARS) modifications of the digital stroke symbol generator. The CIGARS modified console eliminates the need for a separate symbol generator because each console contains its own symbol generation circuitry. The digital stroke symbol generator stores all symbols as digital codes in a group of read-only- memory (ROM) chips or programmable read-only- memory (PROM) chips. In this example, we assume that a PROM is the device that stores the symbol. The computer sends a message to the display group indicating what symbol needs to be painted. The message is translated and the data bits that were used to identify the symbol in the analog symbol generator are sent to the stroke control logic and are used to access stroke codes from a PROM. There are eight distinct routine states or time periods in the symbol routine process as shown in table 1-1. During each routine time, a component of the symbol to be displayed is mechanized. At the start of the symbol generation process, the CRT beam is moved to the location where the symbol is to be painted. Table 1-l.-Symbol Routine States The stroke symbol generator paints the dot first, then accesses the PROM to get the symbol strokes. The PROM has eight outputs for each address. Each output performs a particular function in the generation of the symbol component. The eight output lines used to mechanize the symbol are as follows: Sign X, X, 2X Sign Y, Y, 2Y Z (unblank) W (wait) Figure l-12.—The symbol grid and stroke PROM addresses. Figure 1-12 shows the mechanization grid for the hostile air symbol. A dot in the grid indicates the function is active. The sign bits control the direction of the beam. If the sign bit is active, the beam is moved in a negative direction. The X, 2X, and Y, 2Y bits combine to determine the amount of deflection: 1-12

zero, one, two, or three grid points. The Z (unblank) signal unblanks the beam when active. The W (wait) output is used to ensure the completion of a stroke before the start of the next stroke. The W fiction is normally used to ensure the CRT beam is in the proper position before the beam is unblanked, blanked, or makes a major change in direction. This prevents distortion of the symbol that could result if the beam has not completely finished a stroke or has not been completely repositioned. Referring to figure 1-12, the PROM is addressed and the output is translated. In this example, the first stroke (stroke zero) positions the CRT beam three grid spaces in the -X direction and the beam is blanked. Upon completion of this stroke, the next address is read and translated. Strokes one, two, and three each cause the beam to be deflected one grid space in the +X direction and two grid spaces in the +Y (up) direction while the beam is unblanked. At the end of stroke three, there is a pause (W) so the beam can finish the stroke before changing direction. Strokes four, five, and six each cause the beam to move one grid space in the +X direction and two grid spaces in the -Y (down) direction. Again at the end of stroke six, there is a pause (W) to ensure that the beam deflection is complete. When the PROM address for stroke seven is read, no outputs are found active. This condition signals the logic that the symbol is complete, and the symbol generator moves to the next fictional time period, as shown in table 1-1. DISPLAY SYSTEMS The combat direction systems (CDS) in use on most ships evolved from the original NTDS systems. These systems developed the standards for several digital computer protocols, and the term NTDS is still used to define several of these protocols. The display sub-system is the largest part of the CDS system. Two major tactical display systems are currently used in the fleet. These are the Data Display Group AN/UYA-4(V) and the Computer Display Set AN/UYQ-21(v). Within each system different versions are tailored for each class of ship, according to the mission of the ship. DATA DISPLAY GROUP AN/UYA-4(V) The Data Display Group AN/UYA-4(V) is the most widely used system currently in the fleet. It was developed to refine the limitations of the AN/SYA-4(V) and the AN/UYA-1(V) systems. The AN/UYA-4(V) display group uses third generation electronics (integrated circuit) for all logic functions. The function of the Data Display Group AN/UYA-4(V) is to provide a real-time visual picture of the tactical situation. To perform this requirement, the systems must be able to accomplish several tasks including the following: Sensor data distribution and display Tactical data distribution and display System simulation and testing Figure 1-13 illustrates a typical AN/UYA-4(V) display group. Sensor position data is received from the ship’s sensor platforms (radar and sonar) and sent to a converter for conversion into a form that can be used by the display console. The converted position data is routed to the display console through a distribution switchboard. Sensor video data is routed to the display consoles through the same switchboard. Tactical data is digital data received from or transmitted to the system computer. Tactical data from the computer is used by the display system to generate symbol displays and alert/switch indications on the display consoles. Tactical data sent to the computer is the result of some type of operator action at the display console. System test is accomplished with the system computer and the video signals simulator (VSS). As illustrated in figure 1-13, the VSS can simulate a radar input to the switchboard to aid the technician in fault isolation or provide simulated data for operator training. The tactical data paths can be tested using the various software programs (POFA, PEFT, etc.) designed to run with the system on your ship. 1-13

COMPUTER DISPLAY SET AN/UYQ-21(V) The Computer Display Set AN/UYQ-21(V) is the latest display system in the Navy. It is installed on the newer ships and is replacing older AN/UYA-4(V) systems as part of the new threat upgrade. The AN/UYQ-21(V) system is also configured according to the mission of the ship. A typical configuration could include tactical display consoles, display control consoles, and large screen projection displays. The system also offers expanded symbol sets and locally generated programmable symbols. As with the AN/UYA-4(V) system, the AN/UYQ-21(V) system provides a real-time picture of the tactical situation. SUMMARY-BASIC DISPLAY DEVICES AND SYSTEMS In this chapter, you were introduced to the basic element of most display systems, the CRT. You were also introduced to the two display systems the Navy is currently using. The following information summarizes some of the important points you should have learned. CATHODE-RAY TUBE (CRT)— The cathode-ray tube (CRT) is the focal point in most display devices. It provides a visual display of data for the operator to interface with the computer. The CRT has three functional areas: a phosphor coated screen, an electron gun, and a deflection system. PHOSPHOR SCREEN— The screen or face of the CRT is coated with phosphor, which glows when bombarded with electrons. ELECTRON GUN– The electron gun in a CRT is the source of the electron beam. The electron gun also contains the control circuitry for the unblinking and focusing of the beam. CRT DEFLECTION SYSTEMS– Electromag- netic deflection and electrostatic deflection are the Figure l-13.—The AN/UYA-4(V) data display system (typical). 1-14

two major types of deflection systems used to move the electron beam around the face of the CRT. Electromagnetic deflection systems use a series of coils mounted on a yoke to generate a magnetic field. The strength and polarity of the magnetic field cause the beam to deflect. Electrostatic deflection systems use four deflection plates mounted inside the CRT to move the beam. A voltage is applied to each plate. The polarity and strength of the voltage determine the amount and direction the beam is moved. CRT SCANNING– CRT scanning moves the electron beam around the face of the CRT to create the display. The two methods of CRT scanning are raster scanning and vector scanning. RASTER SCANNING— Raster scanning develops the display by painting a series of lines across the CRT. There are two types of raster scan: interlaced scan and noninterlaced scan. Interlaced scan uses a method of painting all the even lines of a frame from top to bottom, then returning to the top of the CRT and painting the odd frames. It is used in television and low resolution digital monitors. Noninterlaced scan paints each frame as a series of consecutive horizontal lines and is used with most digital monitors. Noninterlaced scan is used to increase the resolution of the display. VECTOR SCANNING– Vector scan CRTs have the ability to move the electron beam to any desired point on the CRT at any time. They are used in oscilloscopes and many radar display consoles. The electron beam is moved to the desired location by using an X/Y coordinate system that defines the exact location of the beam. COLOR CATHODE-RAY TUBES– The color CRT works in a very similar manner to the monochrome CRT. The major difference is that the color CRT has three electron beams that are synchronized to strike dyed phosphor dots on the face of the CRT. These dots are red, blue, and green, the primary colors of light. DISPLAYING RADAR SWEEP, VIDEO, AND SYMBOLS– The AN/UYA-4(V) data display group uses vector scan CRTs in the plan position indicator (PPI). The PPI is usually under the control of the radar sweep logic and switches to symbol display logic when a message is received from the computer. RADAR SWEEP AND VIDEO– Radar sweep originates in the center of the CRT and travels outward until the edge of the CRT or the end-of- sweep signal is reached. The radar azimuth is developed by ∆Χ and ∆Υ pulse trains developed by a piece of ancillary equipment. Video returns are displayed as intensified sweep. SYMBOL GENERATION– Symbols are gener- ated from data messages outputted by the computer. Two methods of painting symbols are used in the AN/UYA-4(V) system: the analog waveform method and the digital stroke method. The analog waveform method uses a separate piece of equipment called a symbol generator. The symbol generator decodes the computer messages and generates X, Y, and Z waveforms to paint the proper symbo1. The X and Y waveforms are applied to the CRT deflection plates, while the Z waveform controls the unblinking of the electron beam. The digital stroke method stores the symbol in ROMs or PROMS as digital codes. The digital stroke symbols are generated by each console when the console is equipped with the console internally generated and refreshed symbols (CIGARS) modification or by a type of symbol generator. DISPLAY SYSTEMS– The Navy currently uses two major display systems in the fleet: the Data Display Group AN/UYA-4(V) and the Computer Display Set AN/UYQ-21(V). Both systems are designed to provide a real-time display of the tactical picture using ship’s sensor data and tactical data from the CDS computer. 1-15

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CHAPTER 2 PERSONAL COMPUTER VIDEO DISPLAYS AND INPUT DEVICES INTRODUCTION The video display is one of the versatile pieces of equipment in a computer system. When used in a large system, it displays the status of computer operations and displays the results of maintenance programs. When used with a personal computer, the video monitor is the primary output device the computer uses to communicate with the user. In addition to having a video monitor as an output device, most computers also have at least one input device, such as a keyboard. The input devices enables the user to control the computer. After completing this chapter, you should be able to: Describe the operation of video display monitors used with personal computer systems Describe the operation of MDA, CGA, EGA, VGA, SVGA, and XGA graphics adapters used to drive video monitors Describe the operation of flat screen displays using liquid crystal display technology Describe the operation of various input devices used with video display terminals VIDEO DISPLAY MONITORS AND ADAPTERS The video display monitor is the primary output device that interfaces the user to the computer. In this section, we cover the different types of video displays used with personal computers. Video displays have two main components: the video monitor and a video adapter. The video adapter is plugged into the PC’s motherboard. VIDEO DISPLAY MONITORS Video display monitors come in a variety of shapes, sizes, and capabilities. They can be color or monochrome, use interlaced or noninterlaced scan, and require either analog or digital (cathode-ray tube [CRT]) drive signals. Composite video monitors are the simplest type of monitor. The video signal is combined on a single line with the horizontal and vertical timing signals before being sent to the monitor. The monitor electronics separate the video signals and the 2-1

The overall requirement of any tactical display system is to provide a visual display of the real-time deployment of ships and aircraft, the tactical situation, and the geographical area of the situation. To perform this requirement, the display system must be able to accomplish several functions. These system functions include: Sensor data distribution and display Tactical data distribution and display Data display group simulation and testing The Naval Tactical Data System (NTDS) has evolved into the Combat Direction System (CDS). Through this evolution, the function and design of the tactical display system has remained fairly constant. On ships with the AN/UYA-4(V) display group, the basic equipment and signal flow are as shown in figure 3-1. The block diagram can be split into three functions: sensor data, tactical data, and simulated data. Each of these functions ties together at the display console. In the this chapter, we look at each function and how it affects the picture on the display console. SENSOR DATA DISTRIBUTION AND DISPLAY Sensor data originates with the ship’s sensors (radar, sonar, and IFF) and is ultimately displayed as sweep and video on the display console as shown in figure 3-1. Sensor data normally consists of two types of data: antenna position and video signals. Antenna position data as it originates from the ship’s sensors must be converted to a form usable by the AN/UYA-4(V) display consoles. Conversion of the sensor antenna position data is accomplished by radar azimuth converters (RACs) or sonar azimuth converters (SACS). In this chapter, we only discuss the operation of a RAC. One converter is required for each of the ship’s sensors. The RAC outputs the timing signals and X/Y quantities necessary to generate that radar sweep display. The sweep data is fed from the RAC to the radar data distribution switchboard (RDDS) for distribution to the consoles. Video signals are fed from the sensor or sensors to the RDDS and then to the consoles. The sweep generation logic of the consoles and timing signals from the RAC ensure that the intensified video is displayed at the proper range on the plan position indicator (PPI) sweep. RADAR AZIMUTH CONVERTER (RAC) The radar azimuth converter, or RAC, converts position data from each of the ship’s radars into a digital quantity usable by the display console and the computer. The antenna position data coming into the RAC maybe in synchro or digital form, depending on the characteristics of the radars installed on the ship. The RAC develops a series of signals known as ∆Υ and ∆Υ pulse trains and the sign of ∆Χ and sign of ∆Υ to send to the display console to paint the sweep in the proper position. The RAC also develops a digital data word that contains the azimuth of the antenna that is transferred to the CDS computer. This data word is known as digital theta and is represented by the Greek letter theta (θ). 3-2

Figure 3-1.—The AN/UYA-4(V) data display system. The ∆Χ and ∆Υ pulse trains are generally developed by using the sine and cosine of the antenna angle. The sine and cosine of the antenna angle will define the angle in a 90-degree quadrant. The sign bits (sign of ∆Χ, sign of ∆Υ) will determine in which quadrant the sweep will repainted. The quadrants and required sign bits are illustrated in figure 3-2. The ∆Χ and ∆Υ pulse trains are sent to the display console where they cause a pair of digital counters to increment one time for each pulse. The number of pulses between the zero mile range mark (start of sweep) and the end of sweep signal denotes the radar sweep angle, and the spaces between pulses indicate the range of the sweep. For example, the sine and cosine of 45 degrees are equal to each other. To paint a sweep at 45 degrees, the sign of ∆Χ and the sign of ∆Υ will both be positive indicating quadrant one. In developing the ∆Χ and ∆Υ pulse trains, the number of pulses for each would be equal. This will increment 3-3 Figure 3-2.—The X/Y quadrants of a CRT.

the sweep counters in the display console at the same rate. The output of the sweep counters is continuously fed to the deflection circuitry, and the beam will be deflected at 45 degrees. Figure 3-3 shows the front panel of a typical RAC. The RACs installed on your ship may not look exactly like this one. On this particular RAC panel, internal testing is accomplished by using the MODE SELECTOR switch. Most RACs have a similar MODE SELECTOR switch that operates in the same basic manner. When the MODE SELECTOR switch is in the OPERATE position, the RAC operates with its radar. The other switch positions of the front panel are used for maintenance and troubleshooting as shown in table 3-1. The RACs are combined together into a cabinet or cabinets called the radar azimuth converter group. The cabinets provide a common power supply and mountings for several RACs. The output of the RACs are fed to the radar data distribution switchboards (RDDSs). RADAR DATA DISTRIBUTION Table 3-1.—The MODE SELECTOR Switch Functions SWITCHBOARD (RDDS) signals (video levels) directly from each sensor. The radar data distribution switchboard (RDDS) The RDDS provides the display consoles access to routes radar and sonar antenna position data and all the sensors connected to the switchboard. The timing signals from the sensor RACs to the display RDDS can accept inputs from 11 radar or sonar consoles. It also receives up to four separate video sensors and provide outputs to display consoles on 10 output channels, one standard display console per Figure 3-3.—A typical RAC front panel. 3-4

channel. Each of the ship’s sensors can be connected, in parallel, to four switchboards to provide sufficient outputs for each display console in the system. Figure 3-4 shows the front panel of the RDDS. When the VIDEO SELECT or RADAR SELECT switches are in the REMOTE position, switching circuits within the RDDS allow the display console on an output channel to select any of the sensors inputting to the RDDS as the source of its sensor display. The display consoles select the sensor (radar/sonar) and video level by sending control signals to the RDDS. In the event of a console control signal problem, manual selection of sensor and video may be performed at the RDDS front panel. TACTICAL DATA DISTRIBUTION AND DISPLAY Tactical data is digital data received from or transmitted to the CDS computer. Tactical data from the computer (output data) is used by the display system to generate symbol displays and alert/switch indications on the display consoles and alphanumeric displays on the digital display indicator (DDI), also called the auxiliary cathode readout (ACRO). Tactical data going to the computer (input data) results from operator actions (switch depressions, trackball movement, and so forth) at the display consoles. Figure 3-5 illustrates the data path of tactical data. This data path can vary depending on the type of system installed on your ship. Systems using the console internally generated and refreshed symbols (CIGARS) modification will not have a separate — symbol generator. Systems using the direct computer interface (CDI) CIGARS consoles will not have the pulse amplifier/symbol generator. In this section, we examine the format of the different data words and messages used by the CDS system. This is followed by’ a brief description of some of the equipment used to display tactical data. COMPUTER DATA WORD FORMATS This section describes the contents and functions of the computer words outputted to the display Figure 3-4.—The RDDS front panel. consoles. 3-5 External Function (EF) Word The external function (EF) word is used to interrogate the addressed console for input data. In addition, for CIGARS consoles, portions of the word

Figure 3-5.—The tactical data path. are used for CIGARS memory load commands. The format of the external function word is shown in figure 3-6. Input Data Words The input data words are formed by the display console logic based upon operator actions. Most operator switch closures or changes will result in the generation of an input word. When the console receives an interrogation EF, the console inputs the input data word to the computer via the pulse amplifier (PA) or direct computer interface (DCI). Each data word sent to the computer consists of a six-bit function code (lower six bits) with the remainder of the word dedicated to data amplifying the function as shown in figure 3-7. For instance, a function code of 00 (binary coded octal) with all zeros in the amplifying data indicates no new data since the last interrogation (no operator switch actions since the last interrogation). A function code of 01 indicates the trackball is enabled. The amplifying data indicates the coordinates of the trackball and range selection of the console. Input data words are developed for the console display control panel and communication panel switch closures, for the trackball and its control switches, and for the digital data entry unit (DDEU) and computer- controlled action entry panel (CCAEP) switches. Output Data Word Types The contents and functions of the computer words generated by the CDS computer and outputted to the Figure 3-6.—The external function (EF) word format. 3-6

Figure 3-7—The input data word format. Figure 3-8.—The address word format. display group are described in the following paragraphs. ADDRESS WORD.— The address word performs two major functions. It addresses or excludes a particular console from acting on the following message data, and it forms the first word of addressed display messages. The address word format is shown in figure 3-8 and contains the address word designator (bit 2 21 =1 and bits 2 20 to 2 15 =0), the console address of the console (bits 2 5 through 2 0 ) to be addressed or excluded, symbol type definition, PPI buzzer commands, auto offset commands, and double symbology commands. VELOCITY/CATEGORY (V/C) WORD.— The velocity/category (WC) word identifies the type of symbol, line, or circle to be displayed. For symbols, the length and type of velocity leader (indicating direction and speed of movement) are specified. One inch of leader indicates 1,080 knots speed for an air track or 33.8 knots for a sea (surface/ subsurface) track. The V/C word format is shown in figure 3-9. It contains the word designator, velocity leader data including scale factor, type (air/sea), X/Y velocity, and symbol data. The symbol data includes category/subcategory, auto/manual and local/remote status, threat, identity, and engagement status. When the V/C word is used-to define a line, the word will indicate if the line is to be solid or dashed. 3-7

Figure 3-9.—The velocity/category word format. Figure 3-10.—The X/Y coordinate word format. Figure 3-11.—The ∆Χ/∆Υ ∆Χ/∆Υ coordinate word format. 3-8

Figure 3-12.—The 48-label readout word. X/Y COORDINATE WORD.— The X/Y coordinate word format is shown in figure 3-10. It is used to define a point on the CRT X/Y grid. This point may be one of the following: the center point of a symbol or circle, the starting point of a line, or the amount of offset in the display. In addition, the word provides symbol modifier (size/upper bar position) and blink (2Hz) commands. ∆Χ/∆Υ ∆Χ/∆Υ WORD.— The ∆Χ/∆Υ word is shown in figure 3-11 and is used with lines and circles/ellipses. When used with lines it defines the length and direction of the line. When used with circles/ellipses it defines the major and minor axis radii. 48 LABEL READOUT WORD.— The 48 label readout word is shown in figure 3-12 and is used to illuminate the computer controlled action entry panel (CCAEP) 48 label readouts. It defines the switch row and column, and the lamp number. It may also be used to energize or reenergize the PPI buzzer. Message Format Output messages to the display consoles are composed of one or more of the computer words we have already discussed. Each message is designed to define a particular display function. Figure 3-13 lists the display message types and indicates the computer words, in order, that compose the particular messages. 3-9 NORMAL MESSAGE.— This message is generated by the computer to locate and describe a particular track symbol and velocity leader to all the consoles. The X/Y coordinate word provides the information to position the symbol on the CRT. The V/C word provides the velocity, category, identity, and engagement status of the symbol, As the message is not addressed to any particular console, the console category selection switching is used to control the symbol display. . ADDRESSED NORMAL MESSAGE.— This message is the same as a normal message except that it is preceded by an address word to address the message to a particular console. ALPHANUMERIC, HOOK, BALLTAB, HISTORY DOT, AND POINTER MESSAGES.— These addressed messages consist of an address word and an X/Y coordinate word. They are designed to display the particular alphanumeric, bar alphanumeric, or indicated symbol on the addressed console only. LINES MESSAGE.— This message is designed to draw a line on the PPI display. The message consists of a ∆Χ/∆Υ coordinate word to define the slope and length of the line, an X/Y coordinate word to specify the starting point, and a V/C word to identify the type of line. ADDRESSED LINES MESSAGE.— This message (not shown) is the same as the lines message except that it is preceded by an address word to address the message to a particular console.

STANDARD CIRCLES MESSAGE.– This message is used to display one of the 13 types of standard circles. The X/Y coordinate word specifies the center of the circle and the V/C word defines the type of circle and therefore its diameter. The standard circles message may be addressed to a particular console. PROGRAMMABLE CIRCLES AND ELLIPSES MESSAGE.— This message generates up to 512 different diameter circles and ellipses. The circle message consists of a circle word (modified ∆Χ/∆Υ coordinate word) which defines the A and B radius of the circle, an X/Y coordinate word that defines the center of the circle, and a V/C word that defines the type of circle. The ellipse message consists of two ellipse words that define the major and minor axis and angle of inclination of the ellipse, an X/Y coordinate word that defines the center of the ellipse and a V/C word that defines the type of ellipse. Both programmable circle and ellipse messages may be addressed to a particular console. OFFSET MESSAGE.– The offset message offsets the display of sweep and symbols to any position on the CRT if the console operator has selected OFFSET on his console. The X/Y coordinate word indicates the amount of offset to the addressed console. PULSE AMPLIFIER/SYMBOL GENERATOR (PA/SG) The PA/SG is actually two pieces of equipment in one cabinet. Several different configurations of this equipment are available and the one installed with your system is dependant on the type of display consoles on the ship. The basic AN/UYA-4(V) system uses the PA/SG configuration. Systems with the CIGARS modification installed will have the pulse amplifier but not the symbol generator. Systems with CIGARS and direct computer interface (DCI) will not have a PA/SG. Figure 3-13.—Display messages. Pulse Amplifier The pulse amplifier (PA) provides for the amplification and distribution of computer input and output data between the display consoles and the 3-10

Figure 3-14.—The PA/SG front panel. CDS computer. Display consoles in tactical systems are divided into two or more display groups, with up to ten consoles in each group. PAs come in three configurations: single channel, dual channel, or 4-channel. A single channel CPA can interface with one computer and one display group. A dual channel CPA interfaces two computers with two display groups, and a 4-channel CPA interfaces up to 4 computers with 4 display groups. Symbol Generator For those systems using waveform symbol generators, there is one SG for each output channel of the PA. A single symbol generator can drive two display groups in the event of malfunctions. In a dual channel PA either computer channel or SG can be used to control both display groups. This switching arrangement allows the display to be divided for 3-11 maintenance (one group for normal operations, and one group for testing) or controlled from one computer for normal operations or system level testing. Figure 3-14 shows the front panel controls for a dual channel PA/SG. The DATA SOURCE switches control the computer and TMG (test message generator) selection for the two display groups (1 or 2). The SYMBOL SOURCE switch controls the configuration of the symbol generators. In the NORMAL position, each of the two SGs drive one display group. The symbol generator can uses analog waveforms or digital strokes to generate symbols. The methods of symbol generation (analog or digital) are covered in chapter one of this training manual.

PLAN POSITION INDICATOR (PPI) 10.7-inch-diameter CRT. Amplifying alphanumeric information is provided by up to two IP-1304 DDIs The plan position indicator (PPI), or display console, is the heart of the tactical display system. The PPI console allows its operator to view the inputs from the ship’s sensors (radar/sonar/IFF) and tactical symbology, to operate in the desired program mode, and to communicate by voice with other consoles, ship’s spaces, or remote ships and aircraft. The PPI display consoles you will encounter in the fleet come in several system and design variations. The PPI console shown in figure 3-15 is a typical PPI. Although we highlight the features of several different consoles in this section, some areas discussed may not be applicable to the consoles on your ship. The display console provides an operator (seated) with up to a 2,000-symbol tactical display on a mounted on top of the console. Each water-cooled console contains its own high-voltage and low-voltage power supplies. The high-voltage power supply (hvps) provides the voltages necessary to drive the 10.7-inch CRT. The low-voltage power supply (Ivps) provides for the logic power and lamp indicators. The console microprocessors and other logic are located in the card box beneath the console bullnose. Front Panel Controls and Indicators The console control panels are shown in figure 3-16. The display, CRT controls, and data entry devices are located for ease of use and maximum flexibility in the console operation. Figure 3-15.—A typical PPI display console. 3-12

Figure 3-16.—PPI console control panels. 3-13

Figure 3-17.—A PPI tactical symbology display. CRT CONTROL PANEL.— The CRT control panel contains the CRT, optional plotting board, and some of the controls for the console. The CRT displays tactical symbology as shown in figure 3-17. The CRT display of sensor data and symbology is controlled from the display control panel. DISPLAY CONTROL PANEL.— The display control panel is located to the right of the CRT and contains the switches and controls to regulate the CRT display as shown in figure 3-18. The BRIGHTNESS section of the panel contains a potentiometer to control the display of video, sweep, symbols, and range marks. It also contains the potentiometer to control the CRT focus, astigmatism, and the centering adjustments. Additionally, the display control panel contains the switches to select the radar, range of the radius of the CRT, select offset, and control symbol leaders. DATA ENTRY PANELS.— For data entry purposes, the console is equipped with a computer- controlled action entry panel (CCAEP), and may be equipped with either a 6 by 7 panel or category select switch panel, a digital data entry unit, or an optional alphanumeric keyboard and a trackball unit. Figure 3- 19 shows a console with the 6 by 7 panel and the alphanumeric keyboard. The trackball is recessed in the trackball well along with the ball tab enable, ball tab center, hook, and sequence pushbuttons. Computer-Controlled Action Entry Panel (CCAEP).— The computer-controlled action entry panel (CCAEP) provides greater flexibility than its predecessor, the mode roller. CCAEPS consist of 24 switches arranged in 4 rows of 6 as shown in figure 3-20. The bottom row of six switches has fixed labels and functions. Each of the remaining 18 switch positions has 48 possible labels, or functions, independently controlled by computer output data and an auxiliary LED indicator. The computer program controls the selection of a Figure 3-18.—A PPI display control panel. 3-14

Figure 3-19.—A PPI equipped with a 6 x 7 panel and a keyboard. label for each switch position on an individual basis. The category selection switches provide for When depressed, each switch position generates a specific function code for computer input. A single LED indicator at the top of the panel is lighted to cue operator responses or to indicate reception of switch function codes. A 6 by 7 Panel.— A 6 by 7 panel consists of 7 rows of 6 switches as shown in figure 3-21. When depressed, each of the 42 switches generates a specific function code for computer input. The 6 by 7 panel is used for category selection and as a data entry unit for numeric data. The top two rows of switches and the first three switches on the left in the remaining rows are used for category selection. The remaining switches are used as a number entry unit. independent console control of the symbology displayed at that console. The console operator can select the category of the symbols to be displayed on the console. The number entry unit consists of a 10-digit keypad, a clear button, and four special-purpose buttons. Numerical entries from the keypad are displayed on the console CRT until one of the special- purpose buttons is depressed and the number entered is accepted by the computer program. Alphanumeric Keyboards.— The alphanumeric keyboard installed in some consoles is a series of switches that inputs a code to the computer when a switch is depressed 3-15

Category Select Panel and Digital Data Entry Unit (DDEU).— Some display consoles use a category select panel and separate digital data entry unit. The category select panel is mounted on the left side of the bullnose and contains the 24 switches to control the display of symbols. The DDEU is mounted in the center of the bullnose and is used for numeric entry as described above for the 6 by 7 panel. CONSOLE COMMUNICATIONS.— The console is provided access to three communications systems-interphone, sound-powered phone, or radio- via the console communications panel and the headset. The console communications panel is shown in figure 3-22. Figure 3-20.—Computer-controlled Interphone.— Interphone links up to 15 consoles action entry panel. with voice and pointer symbol communications. This Figure 3-21.-A 6 x 7 panel. 3-16

Figure 3-22.—A PPI console communications panel. allows the console operators to communicate by voice with each other and identify locations or events on the CRT to each other using the pointer symbol. Sound-Powered Phone.— Sound-powered phones tie the consoles into the ship’s sound-powered communications network. Radio.— Radio provides for ship-to-ship or ship-to-aircraft secure or nonsecure radio communication. Console Functional Description The display console is divided into two major functional areas: the digital area and the analog area. The digital area interfaces the console to the computer and the console operator. The analog area contains the deflection control logic and the intensity and focus control logic that drive the CRT display. DIGITAL AREA.— The digital area receives computer output data, processes it, and outputs deflection and intensity (stroke) commands to the analog area. It also monitors console panel switch status and builds input words as switch status 3-17

Figure 3-23.—Digita1 display indicator. changes. It then transmits the input words to the CDS computer in response to interrogations. ANALOG AREA.— The analog area receives ∆Χ and ∆Υ pulse trains, range marks, end-of-sweep, and video from the RDDS. This data is used to generate the sensor sweep and video display. The digital area of a CIGARS-equipped console provides the symbol control signals (SIGN X, X, 2X, SIGN Y, Y, 2Y, Z, and W) and offset data for sweep and symbology. In systems that use a symbol generator, symbol waveforms and unblinking signals are inputted directly into the analog section. Digital Display Indicator (DDI) The IP-1304/UYA-4(V) digital display indicator (DDI) shown in figure 3-23 is also called digital data indicator. It is a raster scan formatted video monitor. It accepts computer-generated alphanumeric (ASCII) and line display data, stores the data in an internal refresh (video) memory, and converts the stored data into monochrome raster scan video signals. The DDI is capable of displaying sixteen 64- character lines (1,024 characters) in the internal video mode. The DDI is also designed to produce a 525-line TV display, from an external TV source, in the external video mode. The DDI is an independent air-cooled, addressable monitor. It is may be mounted on top of the display console or in a stand-alone configuration as an auxiliary cathode readout (ACRO or CRO). It accepts data directly from the computer (DCI) or through the PA. When mounted on a console, the DDI is daisy chained with the console. The computer output data is routed through the DDI before going to the console digital area. 3-18

DISPLAY SYSTEM SIMULATION AND TESTING Figure 3-24.—VSS front panel. Most tactical display systems are able to simulate radar video and sweep signals for testing, troubleshooting, and operator training on the PPI consoles. In addition, there are computer programs (POFA/PEFTs) specifically designed to exercise the display consoles and verify their proper operation. This section covers the devices and software used in tactical display systems to simulate the ship’s radars and to test and troubleshoot the tactical display system. VIDEO SIGNALS SIMULATOR (VSS) The VSS develops simulated radar video and sweep signals for use in tactical display system testing, troubleshooting, and operator training. The VSS is used in place of or in conjunction with an operating two-dimensional radar. Simulated video and sweep signals of variable characteristics are used in the testing of RACs, RDDS, PPI consoles, and the operations summary console (OSC). Use of the VSS makes it possible to monitor operator tracking accuracy. When used in conjunction with the operational program, the VSS can develop 3-19

simulated tracking and tactical situations that resemble actual operations. Data extracted during these simulated exercises can be used to verify the accuracy of operator tracking and system operation. The VSS is a computer-controlled device capable of generating antenna position data and triggers (sweep data), and radar video signals including simulated tracks, IFF/SIF, receiver noise, and sea clutter. Only the generation of video signals may be computer controlled; all other VSS functions are controlled from the VSS front panel, shown in figure 3-24. Radar Sweep Simulation The VSS can generate its own antenna position data or use a ship’s radar as a source. If a ship’s radar is used, the LIVE RADAR SOURCE switches are used to select the source radar and video level. The VSS then receives antenna position data and triggers from that radar’s RAC via the RDDS. The antenna position data (digital azimuth) and triggers are used to determine the generation times for video signals. The VSS contains its own synchro assembly, which generates synchro azimuth and triggers to the VSS RAC. The output of the VSS RAC is in turn fed back to the VSS via the RDDS for coincidence comparisons. The VSS simulated antenna rotation (RPM) and timing signals are controlled from the SIMULATED RADAR switches. To activate the servo assembly, both the E-REF and ANTENNA switches must be on. Radar Video Simulation The VSS receives video control data from the computer in message form. The output data defines the simulated video azimuth (bearing), range, and intensity. The VSS stores the output data in its track storage and compares the data with the digital azimuth and sweep data received from the RDDS. When the simulated video data and the digital sweep data are coincident, the VSS generates the ordered video signals and transmits them to the RDDS. Console selection of the VSS radar and video level allows display of VSS video and sweep. 3-20 The video output of the VSS is made up of three types of video: live video, live and simulated (mixed) video, and simulated video. The live video output is isolated from the simulator. The live and simulated output is made up of simulated tracks intermixed with live video passing through the VSS. Simulated video is made up of computer-generated video only. Manual control of the simulated video characteristics is provided by the SIMULATED VIDEO switches. These switches allow the generated video to display characteristics that are similar to live radar video. The VIDEO DURATION (µSEC) switch controls the intensity (pulse length) of the simulated video return. The sharpness of the return is controlled by the IF BANDWIDTH switch. The sector width of the return is controlled by the RADAR BEAMWIDTH DEGREES control. TEST MESSAGE GENERATOR (TMG) The test message generator (TMG), shown in figure 3-25, is used to generate simulated computer output data for testing and troubleshooting display equipments. Normally contained in the PANG cabinet, the TMG is removable for its testing and troubleshooting role. The TMG maybe connected to the equipment under test by a jumper cable. This permits greater freedom of action for maintenance personnel in troubleshooting individual devices, such as a PPI console. The TMG can simulate any desired computer output data message up to four data words in length. Coding of TMG data is controlled by word group switches on the TMG control panel. The TMG is capable of operating in five different modes. The mode selection allows for great flexibility when testing or troubleshooting the display suite equipment. Free Run Mode The free run mode of operation repeats an operator-selected four-word message approximately every 400 microseconds. In this mode, the TMG may be used with any display equipment.

Figure 3-25.—Test message generator. Test Pattern Mode The test pattern mode of operation, used only when the TMG is installed in the PA cabinet, displays two symbols repeated every 90 degrees for a total of eight symbols. All the word designator bits and the TEST PATTERN switch must beset too btain this display. The test pattern is normally output to one group of consoles at a time. Output Data Request (ODR) Mode The output data request (ODR) mode of operation generates one data word in response to each ODR received from the equipment undervest. ODR mode is used when testing the PA, VSS, or consoles with DCI. The 2/20 Cycles-Per-Second (CPS) Modes The 2/20 cycles-per-second modes are a variation of the free run mode. The two-cycle mode repeats up to a four-word message twice a second (every 500 milliseconds). The 20-cycle mode repeats the message 20 times a second (every 50 milliseconds). DISPLAY POFA/PEFT A tactical display system is a somewhat complicated combination of equipments. The sheer number of consoles (PPIs), radar distribution switch- boards, radar azimuth converters, pulse amplifier/ symbol generators or PA/CIGARS or DCI/CIGARS tends to present a formidable maintenance task. One of the primary tools available to the maintenance technician is the display programmed operational functional appraisal (POFA) and on some classes of ships, the display peripheral equipment functional test (PEFT). Display POFA The display POFA grouping of tests is designed to be loaded and run in the computer in lieu of the operational program. Display POFA subtests are 3-21

designed to check particular functions of the display consoles and VSS. The display POFA is normally run on a group of consoles as part of the fault isolation process or as required by the planned maintenance system (PMS). The display POFA subtests will vary from system to system, depending on the equipment configuration of the display suite. There are, however, several common functions normally tested. Switch function codes are checked; test patterns of symbols are displayed; the trackball/ball tab coor- dinates are verified; and various panel operations are exercised. The display POFA is designed to com- pletely check all display capabilities. Display PEFT The display PEFT grouping of subtests is contained in the operational program. The display PEFT allows the operator or technician to verify the operation of a single console independent of the operational program in progress. The display PEFT subtests are similar to the display POFA. However, the range of subtests is more limited in the PEFT. The display PEFT is designed to be run on a console in the event a console malfunctions during normal operations. ELECTRONIC PLUG-IN CIRCUIT TEST SET Tactical display systems are equipped with an electronic plug-in circuit test set. The test set, shown in figure 3-26, provides the technician with the facilities to test and repair faulty plug-in assemblies used in the display suite equipments. The test set simulates normal operating conditions by providing operating power and loads to the assemblies under test. In addition, the test set provides test signals and monitoring facilities, which enable the technician to troubleshoot, test, and align faulty assemblies. Portable test equipment (oscil- loscopes, vacuum tube voltmeters, and so forth) is used in conjunction with the test set. SUMMARY—THE DATA DISPLAY GROUP AN/UYA-4(V) This chapter has introduced you to the Data Display Group AN/UYA-4(V). The following information summarizes the important points you should have learned. DATA DISPLAY GROUP— The purpose of any display system is to present a visual picture of the tactical situation. This allows the operator to make various decisions and take action. The heart of the display system is the plan position indicator (PPI), or display console. The PPI receives analog inputs from the ship’s sensors (radar and sonar), digital or tactical data from the CDS computer, and simulated data from the video signals simulator (VSS) and test message generator (TMG). The simulated data from the VSS can be used for system testing or operator training. SENSOR DATA DISTRIBUTION— Sensor data from the radar is received by the radar azimuth converter (RAC) and distributed to the PPIs by the radar data distribution switchboards. RADAR AZIMUTH CONVERTER (RAC)— The RAC converts antenna position data to a form that the PPI can use. The azimuth data is sent to the PPI console as ∆Χ and ∆Υ pulse trains. The number of pulses in the pulse train represents the angle of the antenna, and the spaces between the pulses represent the range of the radar. RADAR DATA DISTRIBUTION SWITCHBOARD (RDDS)— The RDDS provides amplifications of the radar video received from the radar and the azimuth data received from the RAC and distributes them to the PPI consoles. TACTICAL DATA DISTRIBUTION AND DISPLAY— Tactical data is data generated by the CDS computer. Tactical data can be symbol data or amplifying information about a symbol. Depending on the system installed on your ship, the tactical data may be distributed through several different routes. 3-22

Figure 3-26.—An electronic plug-in test set. 3-23

PULSE AMPLIFIER/SYMBOL GENERATOR (PA/SG)— The PA/SG is really two pieces of equipment in one cabinet. The pulse amplifier provides amplification and distribution of computer data to the PPI consoles. The pulse amplifier also receives data from the PPI consoles for input to the computer. The symbol generator decodes data from the CDS computer and generates the symbol waveforms or stroke code to paint a symbol. Systems with PPI consoles that have the console internally generated and refreshed symbols (CIGARS) modification installed will not have a separate symbol generator. In these systems only, the pulse amplifier is installed. Systems with CIGARS modified PPI consoles that also have the direct computer interface (DCI) will not have either the pulse amplifier or symbol generator. PLAN POSITION INDICATOR (PPI)— The PPI receives data from the RDDS and CDS computer and creates a visual display on a CRT. There are several models of the AN/UYA-4(V) PPI. The PPI also allows the operator to input data to the CDS computer. DATA DISPLAY GROUP SIMULATION AND TESTING— The data display group allows for the generation of simulated video and radar signals using the video signals simulator (VSS) and offline testing of most equipment using the test message generator. Circuit card repair and alignment is accomplished using the electronic plug-in test set. VIDEO SIGNALS SIMULATOR (VSS)— The VSS generates simulated video and radar signals for operator training and system troubleshooting. The VSS can generate simulated video using inputs from a ship’s radar system and can mix simulated video with actual live video. TEST MESSAGE GENERATOR (TMG)— The TMG allows the maintenance technician to input up to four computer words to paint symbols on the PPI consoles. This allows the operator to perform offline tests on each individual CIGARS equipped console or one display group. ELECTRONIC PLUG-IN TEST SET— The electronic plug-in test set allows the technician to troubleshoot and align circuit cards and assemblies of the Data Display Group AN/UYA-4(V). Special adapters and cables allow the technician to control the signals applied to each pin of the card under test to isolate the faulty circuit. 3-24

CHAPTER 4 THE COMPUTER DISPLAY SET AN/UYQ-21 (v) INTRODUCTION The Computer Display Set AN/UYQ-21(V) is installed on CV/CVNs, LHDs, AEGIS, and New Threat Upgrade Platforms. Because the AN/UYQ-21(V) is a modular system, its elements can be combined in a variety of configurations to meet the mission requirements of the user. If the user’s requirements change, the configuration can be changed with the addition of new elements. In this chapter, you will learn about the basic configurations and functions of the Computer Display Set AN/UYQ-21(V). After completing this chapter, you should be able to: State the purpose of the Computer Display Set AN/UYQ-21(V) Describe the functions (CEG) components Describe the function switchboard (SDDS) and operations of the central equipment group and operation of the sensor data distribution Describe the function and operation of the different types of display consoles used in the AN/UYQ-21(V) system Describe the function and operation of the television converter group (TVC) equipment The AN/UYQ-21(V) display system provides for the display of tactical information to enhance combat systems performance. Three types of tactical information can be displayed by the AN/UYQ-21(V) system. These are computer- generated data, sensor data (radar, sonar, IFF, etc.), and television data. The operators use this data for the following purposes: Detection, tracking, identification, and evaluation of contacts Assignment and control of onboard weapons systems Assignment and control of other weapons systems (such as aircraft) via radio and data links 4-1