2 Operation Bit (Coil) Calculation Example To determine the Modbus TCP coil for a PLC bit, subtract 1000 from the CIO Channel number, mul- tiply by 16, and add the bit number as shown in the examples below. Command Size Limitations Modbus Function Codes have the following size limitations. Do not attempt to exceed the size limits. 2-3-2 Modbus TCP Master/Client Mode When configured for Modbus TCP Master / Client mode, the adapter functions as a master device, con- trolling the communications with other slave devices such as I/O blocks, inverters, PLCs, etc. The adapter sends Modbus TCP commands to and receives Modbus TCP responses from the slave devices.
This mode is not selectable for use with the CJ2M-series PLC. See 2-1-1 PLC Setup for more information on PLC setup and switch configuration. Grid Connect Modbus/TCP Adapter Application and Setup Guide 2-11 PLC Memory Location Calculation Modbus Coil [ (CIO) 1000 - 1000 ]*16 + 0 = 0 [ (CIO) 1100 - 1000 ]*16 + 12 = 1612 [ (CIO) 1122 - 1000 ]*16 + 7 = 1959 [ (CIO) 1199 - 1000]*16 + 15 = 3199 Modbus Function Code Read/Write Size Limit 03, 04 125 Channels (Registers) 10 123 Channels (Registers) 06 1 Channel (Register) 01, 02 998 Bits (Coils) 0F 998 Bits (Coils) 05 1 Bit (Coil)