synchronnisation of AI AO on multiple devices using PXI

[cquark]

Hi

I have a problem with synchronisation of Analog input and Analog output on multiple devices, but had not problem doing so for multiple channels on the same device. I generate 3 analog signals to drive 3 scanners, I want to be able to output these to 2 devices such that the first 2 signals are applied to the first device and the third signal to the 2nd device. I read the corresponding position feedback signals from each of the scanners. I would like to synchronise the signals output to the devices and the fgeedbacck input signals from the devices. I had generated a code based on Multiple channel synchronisation example under DAQmx  examples, for 2 signals on the same device, that I modified to accomodate a 2nd device based on the Multidevice synchronisation example under the DAQmx examples. But there is an error generated that I would like you help to solve.

Thanks 

[Henrik_Volkers]

Do you use T-Clk?

[cquark]

Hi Henrik

No, I donot use T-Clk

[Davidek]

Hi

What is the error you are seeing?

Best Regards

David

[cquark]

Sorry I had not mentioned the error. 

Error -50103 occurred at DAQmx Start Task.vi:4

Possible reason(s):

The specified resource is reserved. The operation could not be completed as specified.

Task Name: _unnamedTask<2>

Probe connected on the error wire showed an error after the DAQmx Write Task.vi(analog ichannel Nsamp)

the error reads

Error -200802 occurred at DAQmx Write (Analog Wfm 1Chan NSamp).vi:1

Possible reason(s):

Measurements: Write cannot be performed when the task is not started, the auto start input to DAQmx Write is false, the Sample Timing Type is something other than On Demand, and the output buffer size is zero.

Call DAQmx Start before DAQmx Write, set auto start to true, modify the Sample Timing Type, or change the output buffer size.

Task Name: _unnamedTask<3>

Could you suggest more material on synchronisation that I could refer to, to be able to understand how the system works.