Issue
When comparing values of Modbus registers within WorkStation and Modscan the values do not match.
Product Line
EcoStruxure Building Operation.
Environment
- Building Operation Enterprise Server.
- Building Operation Automation Server.
Cause
The third-party Modbus device does not support single register requests.
Modscan was set to poll 10 registers as a group poll and giving the correct responses.
The Modbus request in the Enterprise Server or Automation Server was polling individual register one at a time. This resulted in incorrect responses from the third party device
Resolution
Add a Modbus register group to the Server then add the Modbus points to this group.
This will cause the Server to poll multiple registers in 1 request and get the correct response from the third party Modbus device.
For more information on Modbus grouping refer to the EBO Webhelp Modbus Register Groups topic
