CHMI Alarms not acknowledging
The HMI can only humbly ask the OPC AE server to acknowledge an alarm. If the OPC AE server rejects the acknowledge, the alarm will remain in the HMI. For AC 800M, the controller itself is responsible for accepting the acknowledge.
What is the origin of the alarms?
- SoftAlarms (Alarm Expressions)
- PLC Connect (alarms made in PLC Connect OPC AE server)
- AC 800M
- 3rd party OPC AE server
Your options will vary depending on the OPC AE server in use. All OPC AE servers listed above support "OPC AE Refresh" and it should be enabled on Alarm Collection Definition.
Lack of refresh may result in HMI listing alarms that does not exist in the OPC AE server, such alarms may not be possible to acknowledge.
Alarms can be deleted from alarm list by an administrator. This is recommended for alarms that does not exist in the OPC AE server and therefore refuse to be acknowledged. Ensure refresh is enabled if the OPC AE server support it.
However, if the OPC AE server do contain the refusing alarms, delete from HMI is futile since the alarms will return when refresh takes place.
A third party OPC AE client such as e.g. MrCrilfe (ask regional ABB support for a copy) could be a very valuable test tool in these circumstances.