The CP1W-MODTCP61 allows Omron CP1L, CP1H and CJ2M-CPU3x PLCs to function as slave nodes on a Modbus/TCP network. The adapter can function as either a Modbus/TCP Master or as a Modbus/TCP Slave, but not both simultaneously. The Modbus/TCP Master mode is used to control/monitor IO blocks and other remote devices. The Modbus/TCP Slave mode responds to commands from a Modbus/TCP Master such as a PC or PLC.