Resource requested by this task has already been reserved by a different task.

[eugenius]

Hello!

I'm trying to acquire two analog signals (current - 4-20mA) using a NI9203 module. It's all OK when i try to acquire only one of them, but when i add a second DAQ Assistant in the diagram, i get the error message "Error -200022 occurred at DAQmx Start Task.vi:2 Resource requested by this task has already been reserved by a different task."

What am I doing wrong?

Thanks.

[Rohama_K]

Hi,

It looks like you are reading data from ai0 and ai1 and outputting data to ao0 and ao1. To read data from two channels with NI 9203, you can't have two DAQ Assistants. This device does not allow for simulatinous acquisition. What you can do is when you setup DAQ Assistant, under the Physical Channels Tab, you can select multiple channels for that device by holding the Crtl or Shift key and selecting the channels you want to acquire from. You will notice that multiple channels are highlighted. The output data will then be an array and you can unbundle the information and do post processing. You are going to have to do this for both input and output channels.

Here is a KnowledgeBase that has an example on how to write to multiple analog outputs.