problemwith acknowledging in Alarm&Event disp.

[korst]

hello,
I am using the labview DSC module to monitor alarms in my technology and wonder if anyone could help me with this:

- is there any chance to solve a situation when an alarm occures, then the value goes off (now i still have an active alarm warning on that variable, despite the value is not in the alarm state anymore (that's fine); using "user" mode of ack) and back to the alarm state in a moment. In this situation after I acknowledge the alarm, it still looks like everything's allright, but it is not! I do have a variable in an alarm state without the system recognize it. Is there any chance to solve this, or is it a specific behaviour of DSC and nobody could do anything about it?

- users: i am logged in the labview, working with the alarms but the Alarm and Event Display.vi does not write the user's name in the column "ack user". the only one possibility when it writes the ack user is when the alarm is auto-acknowledged.

- minor question: despite changing the color in the ActiveX Property Browser in front panel or Property node in block diagram, i am not able to change it (or to be precise the only one i can change is the old alarm color).

thanks a lot for your answers, i am desperate about these alarms...

[gelmin]

Hi

If I have understood things correctly then the answer to you're first question might have to do with the dead band settings of you're alarm. This is a feature that is supposed to prevent filling up the alarm list when you're variable is fluctuating close to the alarm value.

Have a nice day, gelmin

[korst]

hi Gelmin,

thanks for reply, but this problem has nothing to do with deadband, because i'm monitoring only boolean variables. my fault, i forgot to specify it.

and other thing i found out: it seems like the DSC alarm engine has switched instructions when to write and who to write in "ack user". In "auto-ack" mode, it writes the signed user int the column, but in "User" mode of acknowledge there is "Nobody". Shouldn't it be vice-versa? Or am i missing something?

korst

[Justin D]

Hi korst,

I took a look at the issues you are having and I was able to reproduce your problems.  I'm not sure what is going on and I'm going to talk to R&D about it.  I will let you know in a few days what happenned.

Regards,
Justin D
Applications Engineer
National Instruments

[korst]

Thanks a lot, i'm really looking forward to it.

korst

[Justin D]

Hello korst,

I've looked into your issues and I have a few answers for you.

1) I'm still looking into this one.

2) The "ack user" question is actually answered in a knowledge base here:
http://digital.ni.com/public.nsf/websearch/4278B27F91CD4BC68625714F006DF4F7?OpenDocument

3) It looks like an answer to your "colors" question can be found here:
http://digital.ni.com/public.nsf/websearch/21CCD299069EC7CD86256BA5006E1D9F?OpenDocument

Regards,
Justin D

Message Edited by Justin D on 02-13-2007 09:39 AM

[korst]

hello Justin,
first of all thank you for spending time trying to help me, I really appreciate that.

I've tried to solve those two problems the way you wrote but:

2) for specific reasons (speed, comfort ...) i am using the ActiveX block Alarm and Event Display.vi on my front panel. and there's the problem how to get information about which line is "clicked" in the ActiveX window to set the shared variable parameter in the "shared variables" input to Acknowledge Alarms.vi, so i cannot acknowledge them the way the link you posted supposed.

3) these fixes are for LV DSC 6.1 and i have version 8.2 (at least MAX tells me this :))

thanks again,
korst

[Justin D]

korst,

Unfortunately, if you want the "acknowledged by" field to be accurate you just cannot use the Active X control.  You would have to create your own display using the DSC alarm VIs.  You're right that the knowledge base article I posted seems to only apply to DSC 6.1.  I tried the dll anyway and it did not work in 8.2 :).  I am going to see if this is something we can easily fix or if it's just something we cannot change for now.

As far as the first error is concerned (that you talked about previously), this is actually a bug in DSC.  When you trigger multiple alarms on a boolean and acknowledge one of them, if the boolean is still in the alarm state it should still show up in the alarms display.  Unfortunately it does not and I have notified R&D about this.  Hopefully they will fix this in the next revision of DSC.

Regards,
Justin D

[korst]

hello Justin,

I've spent a lot of time trying to create my own "code" for displaying the alarms, using DSC alarm VIs, but it was too slow, it takes some 10 seconds to get it working ( P4 3.0GHz + 1GB RAM...) and by that time the computer is not responding to anything. I guess it is a specific behaviour of those DSC VIs, otherwise I don't know And that was the reason I returned to that ActiveX control and found out it isn't a painless way as well.

I just wanted to get it working. At last, I don't care about the colors, I can even stand a fact that the ack users are switched in the non-working-good ActiveX control, but what I do want is to work it properly when handling the re-set alarms as I described above. I've spent about 100-120 hours on this and still don't have the solution...

korst

[Justin D]

Hello korst,

Something that may be a workaround for this problem would be to use integers instead of booleans for your shared variables.  You could still have the boolean controls on your front panel and when you write the value to the shared variable you could use the "Boolean to 0:1" function on the funtion pallette to convert the boolean into an integer.

Regards,
Justin D