Inovance H3U Series - Configuration Table

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9 Communication 9.5.1 Protocol Setting Method for Modbus Conguration Table
9.5 Modbus Conguration and Usage
Programming with Modbus instructions is exible, and user programs are easy to understand. However, if a slave
station is disconnected during communication, the program scan duration will be affected, which will affect control
and may even cause scan timeout alarms. Conguration tables solve this problem.
Dene communication content and data storage units in a Modbus conguration table, and download the
table together with user programs to the PLC. When the PLC executes user programs, system software will
automatically conduct Modbus master station communication. The following describes operations during
programming.
Congure the specied communication port by selecting a Modbus master station protocol and setting the
communication format. Complete the conguration table based on data frequency, address, and trigger condition.
Refresh D variable, trigger M ags, and use the received D variables for calculation. The master PLC regularly
checks the state of each Modbus slave station, determines impact of communication faults on the system, and
gives alarms or shuts down the system.
9.5.1 Protocol Setting Method for Modbus Conguration Table