Allen-Bradley 1771-DB Data Highway Interface Module is a PLC-5 Basic Module that provides a Data Highway interface and a serial port for communicating with Data Highway devices and RS-232C, RS-422A, or RS-485 peripherals. It sits in a PLC-5 1771 I/O backplane and links a PLC-5 processor to external serial devices, enabling data exchange between the processor and DH+ networks or connected terminals, printers, or modems. As a Basic Module, the 1771-DB can execute BASIC-language programs for local data processing and I/O handling within the PLC-5 environment.
