Triggering 6115 with 5401

[UA polarization lab]

I am using the 6115 to acquire two channels of analog input, with an external analog (sine wave) trigger at 3.9345 MHz. When the trigger is supplied from a benchtop function generator (Tektronix), everything works fine. When I use the output of the 5401 functional generator, with the exact same sine wave output in terms of frequency and amplitude, I get error 10805: clock rate is faster than hardware can support. It says this condition may also occur when glitches are present on the clock signal. I have checked both the benchtop function generator and 5401 output on a scope, and they look identical. Is external circuitry needed between the 5401 and the 6115 to make this work? I have also tried digital triggering using the 5401 SYNC output,
but this makes AI Buffer Read hang the computer, even if I set the timeout to a few seconds.

[Adam_U]

I would suggest ensuring that your expected input impedance and output impedance take into account the 6115's high impedance. The Tek generator may be compensating for this high impedance state differently from the 5401.

Also, to determine whether glitching on the line is causing this, see how low you have to make the sample rate before the 6115 works. Then you can use the timestamps of the 6115 to see if we are triggering more often than we expect. You could also do this by setting up a finite acquisition of very few points and checking the timestamp.