Concept
Modbus Upgrade
Depending on your system Modbus might need to be updated.
Modbus Changes after Upgrade from Version 5.0 to Version 6.0
In EcoStruxure Building Operation 5.0 and earlier, Modbus communication used a round-robin scheduling method for all devices. Starting with version 6.0, this approach is retained only for Serial clients. For TCP connections, communication is now always enabled, allowing each Modbus device to maintain its own network queue and TCP connection. This architectural change significantly improves communication speed, especially when managing multiple devices.
After upgrading from version 5.0 (or earlier) to version 6.0 (or later), you may notice slower communication or an increase in offline alarms, particularly with older Modbus devices. It is recommended to run Modbus diagnostics a few days after the upgrade to assess device performance and connectivity.
For more information, see Opening Modbus Diagnostics .
Based on the diagnostic results, you may need to adjust settings or configurations on your Modbus devices to optimize performance.
When upgrading to version 6.0 or later, the following properties in the Modbus Serial Client are removed:
Silent character
After the upgrade the default value is 3.5. The default value follows the Modbus standard and cannot be changed.
Poll delay
After the update the default value is 10 ms and cannot be changed. If this value was changed in 5.0 or earlier, it’s kept and used but hidden.
PSS can assist you if you experience problems related to this functionality and need to update the Poll Delay setting.
Poll delay (%).
Poll delay (%) values are obsolete after upgrade. Modbus communicates in parallel with compatible devices in EcoStuxure Building Operation 6.0 and later.
Modbus Overview
Opening Modbus Diagnostics
System Upgrade Overview