bacnet alarm summary & acknowledgement

Question

I am developing a touch screen device that gets data from field devices using the BACnet protocol. I'm currently developing some pages that show devices alarms. As per BACnet documentation, there is a service named AlarmSummary. When invoke (as a client) this service, field device answers with a list that include, for each alarm, the following information

• object identifier
• alarm state
• list of acked transitions

Now my question is: how can I acknowledge an alarm that I read through the GetAlarmSummary service considering that the AckAlarm service requires the following information to be provided

• Event Object Identifier
• Event State
• Acknowledged Time Stamp
• Acknowledgment Source
• Time Of Acknowledgment

Thanks in advance

Answer 1

In short, you can't or you read the required information in a second step. Use the GetEventInformation service to obtain information about active event states. It returns all information required to acknowledge alarms.

Note, that the execution of GetAlarmSummary and GetEnrollmentSummary is deprecated, see future Addendum 135-2012av. Regardless, initiation will be still required if a device doesn't support AE-INFO-B.