Create two AI tasks for SCXI module

[RajGru]

Hi all,

I have two SCXI-1102 cards. Is it possible to create two Analog Input(Thermocouple) tasks for each SCXI card and run the tasks simultaneously?

Thanks,

Raja

[Brad_K]

Hi Raja,

You might need to add channels from both modules to the same DAQmx task in order to use both modules simultaneously.

If each SCXI-1102 module is connected to a separate DAQ board (E Series, M Series, X Series, or S Series) with a separate cable and is using "parallel" mode, then you can use two separate tasks. If only one SCXI-1102 module is connected to a DAQ board, then you are using "multiplexed" mode, which only supports one analog input task (per DAQ board) at a time.

Brad

[RajGru]

Hi Brad,

Thanks for your reply.

I have a PXI-1050 PXI/SCXI Combination chasis in which I am going to use PXI-6224 Analog card, PXI-2586 Relay Switch & SCXI-1102 thermocouple amplifier.

I have a problem in running the task that i created. I created a task for the PXI-6224 analog voltage channels and another task for SCXI-1102 thermocouple channels. I tried to execute both the tasks parallely but only one task is executed & the other task gives an error stating " Error -50103 occurred at DAQ Assistant Possible Reason(s): The specified resource is reserved. The operation could not be completed as specified."

If I execute the task seperately ie., one at a time, the task runs successfully.

Whether I need to configure both PXI-analog card channels & SCXI thermocouple channels in a same task?

How to configure the task to run parallely, if there are 2 PXI-6224 cards & 2 SCXI thermocouple cards?

Thanks,

Raja

[Brad_K]

Sorry, when I wrote the previous reply I forgot that the SCXI-1102 does not support parallel mode. Only SCXI modules that have 8 channels or less are capable of supporting parallel mode. You will have to acquire from both SCXI-1102s using the same task, as long as they are in the same chassis.

Assuming that one of the PXI-6224s is in slot 8 (the rightmost slot), then DAQmx will acquire the SCXI data from an internal channel on that PXI-6224, which is connected to the SCXI part of the chassis using the PXI local bus. Otherwise, if you have one of the PXI-6224s cabled to one of the SCXI-1102s using a 68-pin cable and an SCXI-1349 or SCXI-1346 adapter, it will use the differential ai0 channel on the PXI-6224's front connector.

Anyway, if you want to put the PXI-6224 channels and the SCXI-1102 channels in the same task, here is how: In the DAQ Assistant, click the Add Channels button to add the other device's channels to the same task. If you were using the DAQmx API directly, you could specify PXI1Slot8/ai0:31,SC1Mod1/ai0:31,SC1Mod2/ai0:31 as the physical channels input to DAQmx Create Channel, or you could call DAQmx Create Channel multiple times with the same task.

Brad