Reference Clock Settings for Counter Output running with Implicit Timing

[manisha.singh]

Hi,

I am trying to synchronize PXI 4461 and PXIe6251. I am using reference clock synchronization. It works perfectly with just analog input tasks, but now I want to add a counter input and counter output to PXIe6251.

This knowledgebase suggests that I need to set the reference clock for all my tasks indiviually. So I did the following:

AI task - set the reference clock to PXI_CLK10 and reference rate to 10MHz

CI task  - set the reference clock to PXI_CLK10 and reference rate to 10MHz

This works if I have only AI + CI tasks, when I add my CO task (which is using Implicit timing using NIDAQmx function DAQmxCfgImplicitTiming), I get the errors

Case 1: When reference clock is set to PXI_CLK10 for CO task 

"NI Platform Services:  The specified resource is reserved. The operation could not be completed as specified.
Task Name: _unnamedTask<173>

Status Code: -50103 "

Case 2: When I do not set the reference clock for CO task.

"Specified route cannot be satisfied, because it requires resources that are currently in use by another route.
Property: DAQmx_RefClk_Src
Source Device: PXI1Slot2
Source Terminal: PXI_Clk10

Required Resources in Use by
Task Name: _unnamedTask<218>
Source Device: PXI1Slot2
Source Terminal: None
Destination Device: PXI1Slot2
Destination Terminal: RefClock

Task Name: _unnamedTask<21F>

Status Code: -89137 "

How can I use reference clock synchronization when I have counter output channels?

Thanks!

Regards,

Manisha

The MathWorks

[Tori_W]

Manisha:

The KnowledgeBase article you referenced explains why you are running into the -89137 error.
Essentially, since both counters are on the same PXIe-6251 device, they have to use the same
reference clock. So the conflict causing this error is between the counter tasks.

For the -50103 error, take a look at this KnowledgeBase: http://digital.ni.com/public.nsf/allkb/485201B647950BF886257537006CEB89.
Do any of these cases apply to your code? Please attach a screen shot of your block diagram
if you would like help determining which case you are running into. I would especially need to see how you are
configuring your tasks and timing.

Also, what chassis are you using and what slots are your cards in? If either of those cards
are in slot 2, which is usually reserved for timing and synch cards, try moving them into
different slots.


Tori W.