Dear all,
I am encountering several problems porting a Traditional NI-DAQ app to NI-DAQmx, while transitioning to new PCI-X hardware.
Configuration
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Vista Service Pack 2
NI-DAQmx 9.1
- PCI-6110
- PCIe-6259
- PCIe-6321
- RTSI cable between the three boards, configured under MAX
- Using straight NI-DAQmx API calls with Delphi
The application uses either 1, 2 or 3 boards depending on user configuration. The program runs simultaneously at least:
- one analog out task on the PCI-6110, 2 analog channels out (Task 1)
- one analog in task on the PCI-6110, 1-4 analog channels in (Task 2), with callbacks every n samples enabled
and optionally:
- one analog out task on the PCIe-6259, 3 analog channels out (Task 3)
- one analog in task on the PCIe-6321, 1-8 channels in (Task 4), with callbacks every n samples enabled
- one buffered timer task on the PCIe-6321, one counter (Task 5) driving analog and digital outputs (Tasks 6 and 7)
- one analog out task on the PCIe-6321, 2 analog channels out (Task 6)
- one digital out task on the PCIe-6321, 8 digital out lines out as a combined port (Task 7)
The program is organized around Task 1 which provides a common trigger and clock for all other tasks, i.e., everyone is synchronized by Task 1.
Weirdness #1
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In a minimal run, only tasks 1 and 2 are involved. Upon user intervention, Tasks 1 and 2 are created, activated, perform their job and are cleared (this is what I call a run).
The bizarre thing is that the callback function in Task 2 works properly only during the second run or afterwards. The first time the sequence
(Tasks 1 and 2 created, run and cleared) is performed, the callback in Task 2 never triggers even if I reset the three devices before the run. I am wondering if this could be an initialization problem in the NI-DAQmx library. The second and subsequent runs work perfectly, all function calls return OK for each run.
Has anyone seen this?
Weirdness #2
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Tasks 4-7, which run on a PCIe-6321 work fine by themselves. When Tasks 4-7 are combined with tasks 1 and 2 (on the PCI-6110), erratic behaviors occur, with intermittent triggering, callbacks in Task 4 triggered only during the first run, occasional crashes in NI-DAQmx etc... Sorry I cannot be more explicit, the program is quite complex. My questions are:
- can you mix PCI, M-series and PCI-X boards through RTSI?
- I don't understand the callback business when a program needs to run several callbacks simultaneously. Do you have to setup the callbacks in a different thread for each callback?
- Do you recommend using one thread per task if this task registers a callback?
Thanks for the help.
