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externally triggered data acquisition on E series troubles
jonny e
Member
08-26-2003 05:24 PM
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I am having trouble getting my 6071E triggered acquisition, and suspect the problem is somewhere in my (linux) driver...maybe some bits that need to be set are not being set...
I can acquire data just fine if the acquisition is NOT triggered externally. But when I try to acquire data using a rising-edge trigger input into PFI0/TRIG1, the acquisition never starts--the program just hangs until I termiante it with good old C-c (I am positive the trigger pulse arrives at PFI0/TRIG1...which I understand from the DAQ-STC manual to power up as an input.)
Here are the bits I set for post-triggered externally triggered acquisition (following the DAQ-STC Tech Ref Manual)--can anyone tell me if I'm completely mi
ssing something, or setting a bit incorrectly?:
AI_Configuration_Start =1;
AI_Trigger_Once =1; (don't want retriggerable acquisition)
AI_START1_Select = 1; (for PFI0/TRIG1)
AI_START1_Polarity =0; (for rising edge trigger)
AI_START1_Edge =1;
AI_START1_Sync =1;
AI_Configuration_End = 1;
A few other things worth mentioning: the pulse being input into the 6071E is coming from the NI 6071E itself (GPCTR_0), or the NI 6602.
When I set AI_START1_Select to 18 (the GRPCTR_0 signal) I still encounter the same problems with the data acquisition never starting
I am actually using comedi, not DDK (is that sacreligious in this forum? 😃 ). For those of you familiar with comedi: I ran the demo programs for acquisition (/comedilib/demo/mmap). It works fine with TRIG_NOW, but TRIG_EXT just makes the program hang...
Any ideas on how to make my triggered acqusition work?
Has anyone had success with DDK (and/or comedi) with triggered acquistion?
thanks much for your help
I can acquire data just fine if the acquisition is NOT triggered externally. But when I try to acquire data using a rising-edge trigger input into PFI0/TRIG1, the acquisition never starts--the program just hangs until I termiante it with good old C-c (I am positive the trigger pulse arrives at PFI0/TRIG1...which I understand from the DAQ-STC manual to power up as an input.)
Here are the bits I set for post-triggered externally triggered acquisition (following the DAQ-STC Tech Ref Manual)--can anyone tell me if I'm completely mi
ssing something, or setting a bit incorrectly?:
AI_Configuration_Start =1;
AI_Trigger_Once =1; (don't want retriggerable acquisition)
AI_START1_Select = 1; (for PFI0/TRIG1)
AI_START1_Polarity =0; (for rising edge trigger)
AI_START1_Edge =1;
AI_START1_Sync =1;
AI_Configuration_End = 1;
A few other things worth mentioning: the pulse being input into the 6071E is coming from the NI 6071E itself (GPCTR_0), or the NI 6602.
When I set AI_START1_Select to 18 (the GRPCTR_0 signal) I still encounter the same problems with the data acquisition never starting
I am actually using comedi, not DDK (is that sacreligious in this forum? 😃 ). For those of you familiar with comedi: I ran the demo programs for acquisition (/comedilib/demo/mmap). It works fine with TRIG_NOW, but TRIG_EXT just makes the program hang...
Any ideas on how to make my triggered acqusition work?
Has anyone had success with DDK (and/or comedi) with triggered acquistion?
thanks much for your help
08-26-2003 06:17 PM
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ok, so i sort of answered my own question...nothing seems to be wrong with the driver afterall...but i seem to be able to trigger acquisition on PFIs other than PFI0. why that is the case i haven't the slightest clue...
but for now, the register settings above do allow for externally triggered data acquisition
but for now, the register settings above do allow for externally triggered data acquisition
Tim_Ousley
NI Employee (retired)
08-27-2003 08:58 AM
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PFI0 is also used for analog triggering. So you will need to disable analog triggering before you can use PFI0 as an input.
This is a difficult bug to identify because it appears to work correctly on boards without analog triggering, and then appears to break when the same code is used on a board with analog triggering ability.
This is covered in Chapter 10 Misc. Functions of the STC Technical Reference Manual.
This is a difficult bug to identify because it appears to work correctly on boards without analog triggering, and then appears to break when the same code is used on a board with analog triggering ability.
This is covered in Chapter 10 Misc. Functions of the STC Technical Reference Manual.
