Unable to use external trigger (TRIG_EXT) on ni_pcimio board

Hi,

We are trying to acquire data with a National Instruments PCI-6071E 
acquisition board. Starting the acquisition using
  cmd->start_src =TRIG_NOW;
  cmd->start_arg =0;
works fine, but 
  cmd->start_src =TRIG_EXT;
  cmd->start_arg =0;
with an external trigger on the PFI0/TRIG1 channel does not seem to get 
the acquisition started. No data is written into the buffer.

We tried blockwaves, sinusoidals and pulses of various voltage 
differences, so it seems unlikely that we are just not using the right 
external trigger. We also tried putting the signal on other channels, but 
to no avail.

We have read the DAQ technical manual and we have tried adding an arming
command and sending a start pulse
(win_out(AI_START1_Pulse,AI_Command_2_Register)) in the ni_mio_common
driver at the end of the ni_ai_cmd() function, but this did not change the
behavior.

Any clue what we are doing wrong?

Regards,
Alexander Heimel & Steve Van Hooser

PS. We looked a little at the source code of ni_mio_common. Could it be 
that in the function  ni_ai_config_analog_trig, the line
  modebits=data[1]=0xff;
should be
  modebits=data[1]&0xff; ?
Although, we are not really using this function at the moment, so we don't 
supppose that this will make an awful lot of difference.

Received on 2002-09-26Z21:04:54