Synchronized analog input on multiple X devices with analog output writes

[smillard]

I have an existing application using a PCI-6353. I need more analog inputs so I added a second PCI-6353 with a RTSI cable between the two boards. The application uses continuous analog input sampling, and single point, analog output writes. I would like to use a single analog input task for both devices. That works until I try to write an analog output. Then I get error -89137:

Specified route cannot be satisfied, because it requires resources that are currently in use by another route.

Property: RefClk.Src

Source Device: Dev1

Source Terminal: 10MHzRefClock

Required Resources in Use by

Task Name: _unnamedTask<18>

Source Device: Dev1

Source Terminal: None

Destination Device: Dev1

Destination Terminal: RefClockInternal

Task Name: _unnamedTask<19>

The sample LabVIEW code below causes the error. The single task, mulitiple device analog input task works if I take out the analog output task. If I remove the dev2 channels from the analog input task, then the VI works with the analog output writes. Do I need to configure timing or special terminal routing for the analog output task?

[John_P1]

When you put multiple X Series devices in the same AI task, DAQmx shares a reference clock between the devices to accomplish the synchronization.  A device can only have one reference clock source though, so your other tasks on these devices need to be configured to use this same reference clock as well.  In your example, Dev1 is trying to use both "10 MHz Ref Clock" and "None" for its reference clock.

Something like this should work:

Best Regards,

[smillard]

Thank you! That works.