Agilent 34401A multimeter to PC with Labview driver via RS232

[Yulia]

Hello!

I am trying to measure a voltage with Agilent 34401A multimeter connected to PC via RS232 cable. I installed the driver. When I am starting Read Single Measurement.vi. It gives me an error:

Error-1073807346 occured at Visa Open in Agilent 34401.lvlib: Initialize.vi->Agilent 34401 Read Single Measurement.vi

Possible reason(s):

Visa: (Hex 0xbFFF000E) The given session or object reference is invalid. 

I would like to ask, how can I adjust my system to use RS23 with Agilent 34401A, if it is possible? If not, should I get GPIB card and cable?

Thank you!

Yulia.

[Dennis_Knutson]

On the front panel, click on the little arrow on the right side of the VISA Resource Name control. You will get a list. Select the com port you are using.

[Yulia]

Hello!

Thanks for your response! Can you, please, tell on the front panel of what? 

I also would like to ask, if VISA version matters for my Labview 8.2 and the NI Agilent 34401A driver for this Labview version? 

Thank you!

Yulia.

[smercurio_fc]

LabVIEW already comes with a driver for the 34401 pre-installed, so I'm not sure I understand what you installed. The pre-installed driver is in the Instrument I/O >> Instrument Drivers >> Agilent 34401 functions palette.

As for the control that Dennis is referring to, it's the VISA control.

As for the VISA version, you should have received a set of driver CDs along with LabVIEW. That will have the minimum VISA version required. Don't remember off the top of my head which version it is. Probably something like 4.1.

[Yulia]

Hello,

thanks! I put com1 and VI runs, but...there is no measurements taken. I think my PC just doesn't see my DMM via RS232. 

I would like to list the software(see attached file), that I can see, when I am opening Measurements& Automation Explorer, can you, please, suggest me if I am missing something, which supposed to be there to allow me to use RS232 port?

Thanks!

Yulia.

[Dennis_Knutson]

If there was a problem communicating, you would get a popup with an error message. What do you have connected to the DMM. What do you read when you operate it manually? Have you tried something as basic as changing the DMM function and seeing if it changes on the meter?

And yes, everything is there.

[Yulia]

Hello!

I am testing the DMM with just a battery taking DC voltage measurement. The DMM works great by itself. I tried Find Meter.VI, and it gives me an error.

Please, see the attached file.

Thanks,

Yulia. 

[Dennis_Knutson]

Where did that come from? It's not part of the driver. Attach it.

Just run the initialize function in the driver. If that runs without an error, LabVIEW is communicating to your instrument.

[Yulia]

Hello!

This is VI from hp34401a.lib, which is in the folder that I downloaded from NI. When I am opening Agilent connection expert, it can not find my DMM, connected to serial ports (it shows red cross next to these serial ports).

I am sorry, but I didn't understand, where you want me to run initialize function. If I am running HP34401A Initialize.VI from this hp34401a.lib, it gives me an error.

Can you. please, give me any suggestion?

I am really stuck, because if all required software shows up in Measurement& Automaton + I have this folder with the driver, which I downloaded from NI, in Labview/instr.lib, I don't understand, what is wrong...

Thanks!

[Dennis_Knutson]

What version of LabVIEW are you using? As already mentioned, a driver for the 34401 has come with LabVIEW for many years and there was no reason to dowload anything. If you have anything greater than 8.0, you are using an older style driver.

It does no good to simply say you got an error. The important information is the error code you get. I don't understand how you can say you get an error with the initialize function when you said you ran the Read Single Measurement. It calls the initialize function so you would have gotten an error then. At least if you were running the current driver. If you had gotten an error instead of just a zero reading, you should have said so.

Agilent connection expert probably requires you to configure it to use NI-VISA.