NI-6111 and Comedi

Hello everyone,

I've been trying to use the NI-6111 DAQ with the Comedi driver, but with
only limited success.  My goal is simply to drive an analog output signal
and to read an analog input signal.  There seems to be some problems,
especially on the input side.  I've read some of the recent archives on this
topic, but I'm not clear as to whether the code now works correctly for this
device or not.

I'm using:
comedi-0.7.65
comedilib-0.7.18
Linux 2.4 (Mandrake 8.1 distribution)
NI-6111 DAQ  (By the way, is the 6111 the same as the 6111E?)
x86 1GHz machine


I believe the build and install went well.  The card is recognized and
demo/info produces reasonable results.  Moreover, I'm able to drive an
analog output with:
  ./outp -s1 [value]

However, there are problems on the analog input side.  The command "./inp"
does not seem to work.  I get errors like "ni_E: timeout 1" and "ni_E:
timeout 2".  Has anyone else seen this?

I looked into the driver code and started experimenting with it.  The
timeout occurs in the function ni_ai_insn_read (in ni_mio_common.c).  It
appears that after the strobe to AI_CONVERT_Pulse, the ADC FIFO remains
empty, no matter how long we wait.  Increasing the timeout value doesn't
seem to improve things.  However, if I strobe the AI_CONVERT_Pulse a second
time, then I get some data in the FIFO (!?).  I'm not sure exactly what is
happening here since National Instruments has not published the register
level description for the 6111.

Does Comedi handle analog input for this device?


Any help or pointers are appreciated.

Thank you,
Juan Gonzalez

Received on 2002-07-15Z22:11:25