Hi, i am using several 34461A DMMs with Labview -> SCPI ->VISA -> LAN -> 34461A.
I want to use the internal memory up to 10000 readings in each DMM to save a long term measurement. I want to set up each DMM to trigger in sync with all DMMs to get readings that were taken at the same time.
When I use the trigger delay and set 10s and use the sample count to 10000 per trigger and send a trigger signal from Labview I can see that my measurements drift away from each other after a few minutes/hours.
I think this is because 1 DMM measures temperature, 1 measures Current and 1 measures Voltage. All DMMs are set to 10 PLC so each measurement has the same length but I think the internal processing is different.
Is there a way other than sending a single trigger from Labview every 10 seconds?
I wanted to unplug and shut down my Labview computer during the measurement....
Greets,
Bernd
I want to use the internal memory up to 10000 readings in each DMM to save a long term measurement. I want to set up each DMM to trigger in sync with all DMMs to get readings that were taken at the same time.
When I use the trigger delay and set 10s and use the sample count to 10000 per trigger and send a trigger signal from Labview I can see that my measurements drift away from each other after a few minutes/hours.
I think this is because 1 DMM measures temperature, 1 measures Current and 1 measures Voltage. All DMMs are set to 10 PLC so each measurement has the same length but I think the internal processing is different.
Is there a way other than sending a single trigger from Labview every 10 seconds?
I wanted to unplug and shut down my Labview computer during the measurement....
Greets,
Bernd
You are correct that internal processing of voltage, current, and temperature measurements may cause the measurements to drift (become unsynchronized) from each other as the ends of the sample counts are reached. To minimize the variation in measurement time between different functions you can try turning off the display, using fixed ranges, and if auto-zero is on (volts, ohms), turn it off.
The trigger delay as you know is between the receipt of the trigger and the *first* reading in the sample count. There is no way to set a delay to pace individual readings.