2 Operation Modbus TCP Slave/Server PLC Setup The CP1W-MODTCP61 adapter uses the Toolbus protocol when operating in the Slave / Server mode. PLC settings are shown below to configure the Option Board Slot. CP1L-L PLCs with one option board slot Switch ON DIP switch 4 to select Peripheral Bus (Toolbus) protocol. CP1L-M, CP1H PLCs with two option board slots Grid Connect Modbus/TCP Adapter Application and Setup Guide 2-3 Switch No. Setting Description Application Default 4 ON Used for peripheral bus (Toolbus). Used to enable a Serial Communications Option Board mounted in Option Board Slot 1 to be used by the peripheral bus. OFF OFF According to PLC Setup.