Modbus Master Point Attributes
Figure 16: Edit Modbus Master Attributes
•Edit Address: Menu selection 1 allows you to edit the network address of the Modbus slave that this point refers to.
•Edit Register: Menu selection 2 allows you to edit the Modbus holding register or input register that this point will access. The type of register accessed (holding or input) will be determined on the basis of the “Read FC” setting (see below). Figure 16 shows an example of how to change the current setting of holding register 1 to holding register 50.
•Read FC: Menu selection 3 allows you to choose the Modbus “read” function code that will be used to read from the designated register. The default setting of function code 03 (read holding registers) will access a holding register on the remote device. By selecting function code 04 (read input registers), a Modbus input register will be accessed instead.
•Write FC: Menu selection 4 allows you to choose the Modbus “write” function code that will be used to write to the designated holding register (this setting does not apply to input registers, as they are
36