I want to have two different operations on two analog output terminals of DAQ. When I work

[SteveChen]

with AO0, it works. But after I add in another channel, AO1, there is an error saying that 'specified group is in use'. Actually, I assigned different group number for AO0 and AO1 when configuing the device using AO Config.vi. How to deal with this error?I want to have two different operations on two analog output terminals of DAQ. When I work with AO0, it works. But after I add in another channel, AO1, there is an error saying that 'specified group is in use'. Actually, I assigned different group number for AO0 and AO1 when configuing the device using AO Config.vi. How to deal with this error?

[Doug_Norman]

with AO0, it works. But after I add in another channel, AO1, there is an error saying that 'specified group is in use'. Actually, I assigned different group number for AO0 and AO1 when configuing the device using AO Config.vi. How to deal with this error?Hi Steve,

Most boards have a single output clock that is shared by the two output channels. If you are outputting on one channel your clock is in use.

Often the solution is to get creative with your output data - you can always output to both channels with 0 volts on the channel you want to be "off".

Regards,
Doug Norman

[RIO-Todd]

with AO0, it works. But after I add in another channel, AO1, there is an error saying that 'specified group is in use'. Actually, I assigned different group number for AO0 and AO1 when configuing the device using AO Config.vi. How to deal with this error?Hey Steve,

Doug is correct. Both analog outputs have a shared clock. If you want to write to both outputs simultaneously, you will need to include both of them in the same operation (group).

You can write a 2-D array to the AO Write VI in which you can include data for both channels. In the 2-D array, column 1 will be for the first channel in the channel list and column 2 will be for the second channel.

I hope this helps.

Regards,

Todd D.
NI Applications Engineer