Pierce Brady

If longer delay is allowing a good outcome, it implies a difference in the time constant of your DUT.

• Not necessarily, it could also be related to the relay contact settling time. 

Does it stop reporting the overflow if you turn off the open lead detection? 

• No.
• It's important to note, that it's not a constant overflow error.
• Typically there will be at least 1 overflow error on each scan and the overflow will be on a different channel each time

I had shortened one of set of leads before making the initial post, but it had no impact.


The overflow problem occurs at 1 and 10 Ohm ranges, but goes away at the 100 Ohm range

I have also tried increasing the NPLC window from 1 NPLC to 3 NPLC but again, there was no impact. 

I gave the oscilloscope a shot with a differential probe but I couldn't really see much
- I didn't see any little square wave or pulse, that would look like an ideal measurement
- Front panel: couldn't see anything on the scope
- Rear panel: I did see spiking for all measurements, regardless if there was an overflow or not 

Could noise pickup on the cables be a potential culprit ? 
 

 I am experiencing overflow errors on my daq6510 and 7702 card. 


The system is setup to measure 4-wire resistance @ 1NPLC cycle, 10 Ohm range with open lead detection. 

At the moment I have it setup to measure 5 Channels. But I keep getting a lot of overflow errors. 
If I change the Channel delay to 50ms or increase the measurement range to 100 Ohm, I no longer experience overflow errors.
 
But these are not the settings I want.
I also have a second system setup to measure 20 channels, with the same settings and that does not experience any overflow errors.

Any ideas on why this is? 
I assume the system manages its own response and settling times.

How do you set the sample rate of the front panel measurement system when measuring resistance ? 

I can see settings to change the aperture time, reducing this increase the sample rate but I have to figure out the sample rate based on measurement timestamps

In the basic setting there is a basic option to set the reading per second but this seems to be more of a system setup setting, i.e. numerous other settings are changed 


It's not clear how I explicitly set the acquisition rate to 10kHz