A 6 by 7 Panel

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