NI DAQ External Clock different to Sample Rate

Hi,

I have NI DAQ 6341 connected to a desktop. I would like to clock the DAQ with a 10MHz square wave (on input PFI0) and then sample from an analogue input (ai0) at a rate of 1k samples per sec. Hence the clock rate and sample rate are very different.

Sampling normally works:

d = daq.getDevices
s = daq.createSession('ni');
s.addAnalogInputChannel('Dev2','ai0','Voltage');
s.Rate = 1000;
s.DurationInSeconds = 1;
data = s.startForeground();

But Adding a clock then seems to cause problems:

d = daq.getDevices
s = daq.createSession('ni');
s.addAnalogInputChannel('Dev2','ai0','Voltage');

addClockConnection(s,'External','Dev2/PFI0','ScanClock')

s.Rate = 1000;
s.DurationInSeconds = 1;
data = s.startForeground();

The errors that I get are either:

With rate of 1000

"Timeout expired before operation could complete."

Or with rate of 10e6 (equal to the external reference clock)

"Rate cannot exceed 500000 in the current configuration."

I understand this error as the NI DAQ can't sample that high.

So the basic problem is that I can't sample with an external reference clock using a sample rate below the external clock rate.

Many thanks for any advice on this issue.

Matt