DAQmx error -50103 for Concurrent analog in tasks

[mgrieve]

When attempting to start the 2nd concurrent analog input task under DAQmx (DAQmx Start Task vi) I get a "specified resource is reserved" error -50103. I can successfully run a digital output task concurrently with an analog input task.. but not the 2nd analog task. Analog tasks tried include multiple channels, single channels, multiple samples/channel, single samples/channel, same SCXI chassis on 2 tasks, and different SCXI chassis on the 2 tasks. The 1st task will read correctly, and if a timer is added to delay the starting of the 1st task, the other task will start and run correctly with the 1st task then failing to start with the same error message. Different names are used for the 2 analog tasks. No overlap of c
hannels between the 2 tasks.

[gaving]

Mgrieve,
This is a problem with the internal circuitry on the board. You are not allowed to have more than one task running (simultaneously) of the same type (like Analog input) because the internal circuitry is already reserved. The only way you will be able to do this is to add both channels you need to the one Analog Input task and read/write to the channel of interest at that point in the code. As you found out, digital is not in the same circuity, so it is allowed to be in a different task running simultaneously.

-Gavin G
Applications Engineer
National Instruments