Fast readings with Keithley 2010 Multimeter?

[Lars Christiansen]

Hi!

I'm a newbee to LabView and am trying to control a Keithley 2010
Multimeter using GPIB and the driver from Keithleys homepage.

I have managed to make a VI, that makes a single voltage read from the
2010, but using that method, I can only read 0.7 times pr second as
the fastest. And that is not fast enough!

How do I get readings faster? I have experimentet with the other
components in the driver, but without succes this far. Maybe because i
configure them in the wrong way, but I'm not sure. I want to make
measurements with delta t time steps N times.

Which VI's in the driver package should I use?

I use LabView 7 and am right now using a simple power supply to test
on.

Thanks for your help!

Lars
Stud.Scient
Univer
sity of Copenhagen

[wha@atmel]

Hi Lars,

find attached a small "performance-test.vi" for
KEITHLEY K2010 - DMM. I have nothing changed @
original drivers - maybe you should play with
all of existing parameters.
At that stage the readings of prog. below are a
little bit faster as you explained - maybe not fast
enough. You should look into the manual of K2010;
Chapter "Buffer Operations"
The Model 2010 has an internal buffer to store from
2 to 1024 readings - this might speed up ......
Use this mode in case my example isn't fast enough.

regards
Werner

[Dennis_Knutson]

I haven't used the instrument but looking at the driver, I would think that the example called Keithley 2010 Multi Read Example is the one you want to use. It will take multiple readings based on internal timer, external trigger, bus trigger, etc. and then return an array of readings. This should be much faster than a single read.

[Lars Christiansen]

Thanks!

The files work - after I changed the decimal separator from , to . on the computer. It runs with about 33 readings pr second. I will have to check with my boss to see if that is good enough, as soon as he is back from a conference. If not, I will look further into using the Multi Read Example (in the driver package from Keithley), which I haven't had much succes with this far.

Yours, Lars.

[wha@atmel]

Yes, you are right with comma and decimal point. I prefer to work with original english version. Often a program got stuck, if on a target machine in Germany or .... the comma is the standard decimal point.

Dennis already pointed to the right direction, but yesterday I was not successful to open the "old" driver with LV6.1 - version. With LV5.1 from an evaluation CD it was possible - now you can try the "multi read example.vi". It worked perfect in our Lab.

regards
Werner

[Lars Christiansen]

Great with some help! Else I would be most on my own, since the "LabVIEW knowing people" in the department, where I work this summer, are on holiday these days.

I have used the Multi Read Example.vi to create a VI, that sends one message to the DMM to make N readings with a specifieddelay and NPLC. It then send the reading back to the VI and displays it on a graph.

The last couple of days, I have tried to solve these two problems, but with no succes:

1) What is delta t between the readings, that I recieve? It should be at least the chosen delay + NPLC times 20msec, but I can see from the graph I make and by changing the input voltage with a known frequency, that delta t is bigger than expected.

2) I sometimes g
et a "error - 410" (query interrupted) on the display. It seems to come, when I put the NPLC, the voltage, the delay or the count value too high. I keep the count value below the 1024 readings, the DMM can keep in its buffer. Even though I get an error (and then usually only an array of zeros as result fo the reading), I can manually find the correct readings in the buffer on the DMM.

Is it a memory problem? Maybe some kind of time out? I have read through the DMM manual, but with no result. I have also run a series of tests varying the NPLC, voltage etc.

Relevant VIs and files are attached. I tried to create a library for the relevant VIs - hopefully it worked!

Yours,
Lars.

[wha@atmel]

Hi Lars,

sorry for late response - but I was on business trip....

Find attached your vi with some minor changes - you should
avoid the "autorange" function, if you need fast readings from an instrument
- take "manual Range" instead !!! Find comments in Diagram.

Enjoy in my "personal icon"

Hope this helps now.
Regards
Werner

[Lars Christiansen]

Nice! Works fine now! In the mean time my boss came back (from Russia) and told me, that he won't need to make measurements at a high rate, so using a "single read" method will be sufficient and I've ended up designing the program in a different way. But thank you for the help! I will probably incorporate the "multiple read" method in the program later - it might come in handy later. I don't understand though why a high resolution is important. The K2010 DMM Manual tells me, that the output (throught the GPIB) is not influenced by the precission (the number of digits on the display). Chosing Manual Range makes sense though.

Cool icon! Werner!!

Thank you again for the help!
Lars.

[Sfax]

Hi,

I am using the 2010 Keithly DMM. And i want to read more than 1024 samples of current (DCI), but the Keithly is looks able to read only 1024 values. Is there any solution to solve this problem???

Thanks for reading 🙂

[RanaY]

Hi,

I'm totally new to Labview so my question may seem very basic.

I have a Keithley 2010 and an hp 4339a(which now belongs to agilent). I wanna use hp as a power source to provide keithley with a constant voltage then of course i need to read the currents measured by keithley and then I'm gonna need labview to draw a VI graph for me. the thing is I need to apply the voltages after a ceratin time interval. This all seem very complicated to me as I have never worked with any of these devices or Labview before so i basicaly have no idea how to do it. Am I using the correct power source? and does anyone have any idea how it's done?

Many Thanks in Advance

Rana Yekani

Technical University of Darmstadt