Problem with alarms in LabVIEW DSC module

[gelmin]

I'm using LabVIEW 8.2 with DSC where I'm trying to define some alarms. My alarm information will be accessed as bit information in a int16 variable from a PLC. The different bits in this variable represent different alarms. I have looked in on the possibility of using a shared variable of the data type U32 Bit Field with alarming. The problem though is that I can't find a way to define several different alarms to the same variable. I have only managed to define one alarm for one specific bit pattern. Is this really the case or have I over looked something?

If this doesn't work I will probably have to create custom alarms using the "Set User Defined Alarm.VI". The only problem with this solution is that I haven't found a way to acknowledge these user defined alarms one at a time. With "Acknowledge Alarms.VI" it is possible to chose acknowledgement by shared variable name, by instance or by area. I can't use the option for shared variable name because I don't have one linked to the specific alarms. Acknowledgement by area is also out of the question because I only want to acknowledge specific alarms and not all in an area. Using instance information to acknowledge would be perfect, but I can't seem to get this solution to work with the user defined alarm. I have tried using a URL similar to the following without any luck, although this is the one appearing in the alarms list:

\\Computer\Process\UserDefinedAlarm.Alarm.

Does anyone know of a solution for this problem or do I have to define one shared variable for each of the alarms? I would really appreciate it if someone could give me some pointers on my problems.

Thanks!

[Matthieu Papaux]

Hi gelmin,

In LabVIEW 8.2 and DSC 8.2 there is no possibility to have one int16 and assign every bit to an Alarm.
Sorry but what you must do is to define every alarms with one shared variable. After that you can use the "Set User Defined Alarm.vi" to configure the user alarms and the "Acknoledge Alarms.vi" to acknowledge it.

Sorry but there is no other possibilities.

Best Regards and have a great Day.

Matthieu

[gelmin]

Thank you for you're reply matthieu.

This is what I was fearing, but I guess it's the only option. It's strange though that this possibility doesn't exist. Alarms from PLCs and other equipment is often transferred as bit information in for example some kind of integer. I guess NI has some improvement potential on this one.

Best regards, gelmin

[Matthieu Papaux]

Hi gelmin,

Sorry but I'm sure that there is no possibility.
The Alarms is programm in LabVIEW and not on the PLC, that the reason because you can use only one bit from a byte...

Best Regards
Matthieu