Agilent 34973A increase the acquisition speed for ac voltage

[spayd]

Hi,

I made a program for data acquisition of 3 signal, temperature and 2 ac voltage. However,the ac voltage channels are open too long and i need datas more often. now i have the measures every 1 or 2 secand i want them every 1/5 or 1/10 sec. i think a solution is  make the actuators do open for those channels but i don't know how proceed or if you have others solutions could you share those with me please

[rleonard3]

Hi spayd,

This is the LabVIEW forum but your issue is with Agilent hardware. I encourage you to repost your issue in the "Instrument Control (GPIB, Serial, VISA, IVI) forum to recieve the best support: 

http://forums.ni.com/t5/Instrument-Control-GPIB-Serial/bd-p/140

[jamiva]

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@spayd wrote:

Hi,

I made a program for data acquisition of 3 signal, temperature and 2 ac voltage. However,the ac voltage channels are open too long and i need datas more often. now i have the measures every 1 or 2 secand i want them every 1/5 or 1/10 sec. i think a solution is  make the actuators do open for those channels but i don't know how proceed or if you have others solutions could you share those with me please

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I don't know what AC meter you are using, but I'll take a wild guess as to what is happening.

You have an enum "4 1/2" wired to the AG34970. I have other instrument drivers with similar inputs. It probably defines the number of digits of resolution of the instrument. The more digits, the longer the dwell time to make a measurements. Plus, you have all your measurements wired serially. i.e., first you take the temperature, THEN the first AC reading, THEN the second AC reading. It's no wonder it takes a second or two.

Then only way around your hardware time limitation is to:
   reduce the precision to "3 1/2" or less, or
   take all three readings in parallel.

[GerdW]

Hi spayd,

now i have the measures every 1 or 2 secand i want them every 1/5 or 1/10 sec.

Your first idea should be to read the manual of your device!

There should be a specification sheet telling you the max samplerate the device offers depending on measurement type and settings…

Once you found all the numbers you need you only need to configure your device according to the suggested settings!

Btw. why do you use InsertIntoArray when you want to Build an Array? And why do you use local variables when the terminal/value is available by wire in the loop?

take all three readings in parallel.

@jamiva: I don't think those DMMs allow real parallel measurement on several channels. Usually they allow to configure some semi-automatic switching of the channels and storing data in an internal buffer to increase sample rate. But then again: all this is written in a manual…

[RTSLVU]

DONT USE THE "EZ" vi's.

You have to configure each channel and a scan list.

Then you scan the instrument when you want to take a measurment. 

To speed up AC measurments on a 34970/2A you can do these things

First turn off auto range and configure the range you need

Reduce the integration time, either set the PLC to .02 or use aperture and set it to minimum.

Remeber this is NOT a highspeed DAQ and it can only measure one channel at a time.

 See this thread http://forums.ni.com/t5/forums/v3_1/forumtopicpage/board-id/170/message-id/923479/thread-id/923479 about three replies down I show how to properly configure and scan a 34972A