BENTLY 135473-01 Slave Station Holding Register

BENTLY 135473-01 serves as the Modbus master station, with the Modbus address consistent with the address in the PLC manual, such as the MBUS of S7-200 serving as the master station_ The MSG instruction is used to send request messages to the Modbus slave and process response messages returned by the slave. When reading the address area starting from I0.0 of the slave station (another S7-200), its input parameter Addr (Modbus address) is 10001. When the starting address of the V storage area of the BENTLY 135473-01 slave station holding register is VB200, to read the V storage area starting from the slave station VW200, the address of the holding register is 40001.

The programmers of computer software (such as DCS or configuration software) for BENTLY 135473-01 need to write programs to implement Modbus communication, and first need to determine the message structure of Modbus RTU. They are generally not familiar with PLC, so PLC programmers often need to discuss the message structure of Modbus with the programming personnel of the upper computer software. The Modbus address provided in the BENTLY 135473-01 manual is the same as the address used by Modicon and GE PLCs, based on a 1 address, which means the first address of similar components is 1. BENTLY 135473-01 uses a zero based address, which means the first address of similar components is 0. The Modbus address of BentlyPLC in the Modbus message also uses a zero based address.