Specified resource reserved with counter

[Salinvo]

Hi,

I'm pretty new to Labview and want to find some solutions with the infamous NI-DAQmx error-50103 'The specified resource is reserved'.

I'm using NI 9189 cDAQ Chassis with two DO module NI 9475. I want to generate PWM with counters of NI 9475 to control fan speed. The task is that four tiny fans will be controlled with lower duty cycle and other two big fans with higher duty cycle. When I run the program individually, it works well. No error happened. But When I try to run both of them simultaneously, the error 50103 occurs. I found the problem is that I can not use NI-9189 Mod1ctr0 and NI-9189 Mod2ctr0 at the same time (same situation with NI-9189 Mod1ctr1 and NI-9189 Mod2ctr1 ). It's okay if I use NI-9189 Mod1ctr0:1 and NI-9189 Mod2 ctr2:3 with these two NI 9475 DO module. But If I want both of them can be accessed with two NI 9475 using counter output. How can I solve this problem?

Maybe the problem here seems stupid. Does anyone can help? The Labview program I'm using is attached.

Thanks in advance for anyone who can give me some clues.

Best regards

Jung

[Kevin_Price · Accepted solution]

Your digital modules have no counters on-board, the only counters you have are the 4 embedded in your chassis.

I have very limited experience with cDAQ, but I believe that channel designations like "Mod1ctr1" cause DAQmx to use the chassis' internal ctr1.  That would explain the conflict you mentioned when 2 distinct modules were each wanting to use the same internal chassis counter.

Further, with only 4 counters to draw from, you won't be able to make 6 counter PWM tasks to control 6 fans.   You'll need to add hardware (perhaps a cDAQ counter module or another cDAQ chassis).

-Kevin P

[Salinvo]

Thanks. That would be reasonable for the situation I met.