EXT_TRIG command hanging

Hi all, sorry to bother the list again:
I work with a NI 6071E board and am trying to trigger analog acquisition
using an external trigger coming in on external pin, PFI0/TRIG1.
I want the board acquisition to trigger on the rising edge of a pulse
received on the trigger pin (PFI0/TRIG1) (The pulse I send it is ~50ms,
or so, from a NI6602).

I successfully ran mmap.c (in comedilib/demo) and then modified it for
external triggering.
I changed the command start_src to EXT_TRIG (it was TRIG_NOW) and left
the start_arg as 0 (for PFI0).
When I do this, recompile, and run the program, sending a pulse into the
proper trigger pin, the program just hangs. (I'm positive the trigger
pulse does arrive on the proper pin.)  

Has anyone else experienced problems with external triggering before? 
If so any ideas on how to fix this?  

I looked through the NI DAQ-STC RLPM and ni_mio_common.c and thought
maybe AI_START_Polarity needed to be explicity set to 0 (for rising edge
detection).  I did modify the driver in this way, but mmap.c still hung.

Thanks in advance for any help you can offer,
jon e

Received on 2003-08-22Z17:29:28