There are two RS232 connection cables for connection to Omron PLC's. The NT21 can be connected to either the miniature programming port of a CPM2C and CQM1H PLC or to the RS232 port of any Omron PLC. By connecting port 2 of the NT21 to the PLC, port 1 is left free for the programming tool NT Shell ( 400-6478) or connection of a bar code reader. Use RS232 cable ( 216-4667) for connection to a personal computer.