The Allen-Bradley 1770-KFA keytop overlay is designed for use with any PLC-2 family processor. The 4 types of industrial terminal systems include the 1770-T1, 1770-T2, 1770-T3, and the 1770-T4 system types and they all have one or more keytop overlays that are shipped together with the keyboard. The Allen-Bradley 1770-KFA keytop overlay is used with just one type of industrial terminal system which is the 1770-T3. To install the 1770-KFA keytop overlay on the keyboard, the users need to align the keytop overlay’s notches with the keyboard’s tabs. The 1770-T1, 1770-T2, and 1770-T3 systems use similar operating codes and keytop overlays while the 1770-T4 industrial system uses different operating commands and keytop overlays for its alphanumeric mode.

When installing the 1770-T1 and 1770-T3 industrial terminals, it is important to ensure that all the peripherals have been installed correctly. The users can use the following procedure to connect the industrial terminal to the processor. First, at the rear of the industrial terminal, attach the PLC-2 program panel interconnect cable to Channel A. Second, attach the other part of the cable to the socket labeled as “INTFC” on the processors' front side. Third, position the Allen-Bradley 1770-KFA PLC-2 family keytop overlay on the keyboard. Fourth, plug the terminal’s power cord into the power source. Last, switch on the power on the industrial terminal. The 1770-KFA keytop overlay has an ambient operational temperature range from 0 to 55 degrees Celsius and an ambient storage temperature range of -40 to 65 degrees Celsius. Also, it has a non-condensing relative humidity level between 5 and 95 percent.