trigger detection in visa

[mathhtam]

hi all ...
I'm using labview 6.1, and i'm trying to command several instrument connected on multiples GPIB cards.( Hp54542A, TVS641, 641A in VXI format, TDS5XX and other instruments). In fact, all this instruments are triggered by only one trigger, and i would like to detect when one or several intrumments are triggering, in order to transfer data to file.
So, my problem is to detect the trigger. I try to use several labview fonctions as "wait for GPIB RQS", GPIB status and i'm loking for DTAS bit which seems to show us that the instrument trigg. But in fact it doesn't work any more. The only response i've is the timeout one. So is there an easy way to build a fonction to detect the trigger? or is there anything i missed to do ? ( with my two
gpib cards, i use ID 0 and ID 1 with labview internal fonctions... )

so help please...

[Dennis_Knutson]

You should be polling the instruments to see if they received a trigger by reading it's status byte register (bit 0 is TRG) or set the SRE to generate a service request when a trigger is received.

[mathhtam]

Thanks for your answer but in fact the problem is that the number of instruments is not constant and could be different. There is so many instruments that i like to find an easyer solution. I like to know, if the status byte is for a particular instrument or for the controler?
So if it's for each instrument, I've to check all the TRG bit to see if one or several instruments trig ? Well .. it seems to be heavy in communication.. and in processor activity

well .. i'll try any more.

Thanks for all .. bye

[Dennis_Knutson]

The status byte is for a particular instrument but if you program the instruments you have to generate a service request when a triggr happens, then you do a poll to see which instrument(s) have asserted the RQS.