From my experience1. Legend
Modbus Slave is addressed with the IP and ID.
Health Timeout is the time that communication module is going to wait for an answer.
Rep Rate indicates how fast the polling will take place.
Read Ref Master and RD Master Object is the location where obtained data are stored.
Read Ref Slave is the Modbus address in Slave memory.
Length is simply the number of registers to read.
Last value indicates behavior on communication failure. Two options are possible: Hold Last and Set to 0.
2. Concept IDE
Below there are two examples of IO Scanning configured in Concept IDE. In the Master Module box, we can select the communication module on which IO Scanning will be configured. In case of Momentum PLC, only CPU is equipped with ethernet port, and we don’t have a choice. In case of Quantum controller, we can install several modules in different slots and configure them individually.
2.1 Momentum 171 CCC 960 30
2.2 Quantum 140 NOE 771 01
3. Unity Pro IDE
Below there are two examples of IO Scanning configured in Unity Pro. The interesting part is that we can set any number of registers and Unity Pro will divide the communication for several parts limiting frames up to 125 registers per poll as per Modbus specification. Here, for the “RD Master Object” we need to refer to a register through “%MW” prefix.
3.1 Quantum 140 NOE 771 11
3.2 M340 BMX NOE 0110
