Instrument Control (GPIB, Serial, VISA, IVI)

cancel
Showing results for 
Search instead for 
Did you mean: 

Agilent 34970 "Not able to execute command in local mode" when operating over USB adapter

Solved!
Go to solution

I'm working on a piece of LabView software and and can't seem to take readings from the Agilent 34970 Data Logger we're working with when we use USB to connect to the instrument. I'm able to take readings and communicate with the instrument over Ethernet, but the USB connection just produces the error "Not able to execute command in local mode".

 

It sounds like there should be a pretty simple fix - I just need to take the device out of local mode - but... I don't know how to do that. I've looked through the manual for the device and tried some google-fu but can't figure it out.

 

This is my first real LabView project and I think my inexperience is getting the better of me. Does anyone have any pointers?

0 Kudos
Message 1 of 13
(7,325 Views)

Did you try pressing the "Local" button on the device front panel (not in LabVIEW)? Apparently the screen should become dark.


GCentral
0 Kudos
Message 2 of 13
(7,312 Views)

I have tried that it it does not work. The manual I have states "You can only disable the front-panel display by sending a command from the remote interface (you cannot disable the front panel while in local operation)." the local button is used to return the device to local mode from remote mode. I'm having issues with finding what command I need to send from the remote interface. I've been using the easy/quick start/whatever VIs and they don't talk about local or remote modes at all.

0 Kudos
Message 3 of 13
(7,309 Views)

My apologies:

 

SYStem:REMote is I think the command you want. See page 269 of the manual (I think 🙂 ).

 

Edit: I'm not certain I'm looking at the right model - I don't see a USB or ethernet port... Are you using a GPIB to USB adaptor? Alternatively, the 34972A has USB and ethernet ports.


GCentral
0 Kudos
Message 4 of 13
(7,305 Views)

Did you check if the instruments USB interface is enabled ? See page 56 of the instruments manual. 

0 Kudos
Message 5 of 13
(7,295 Views)
SYStem:REMote is I think the command you want. See page 269 of the manual (I think).

I think you are correct, but I'm not clear on how to issue this command in my LabView program. I looked through the VIs in the instrument driver and couldn't find anything related to toggling the mode of the device.

 

Did you check if the instruments USB interface is enabled ? See page 56 of the instruments manual. 
I'm not certain I'm looking at the right model - I don't see a USB or ethernet port... Are you using a GPIB to USB adaptor?

The model we're using is an Agilent 34970A, the one without on-device USB or Ethernet connectivity. We're using an adapter to convert the GPIB connection in both cases. Agilent's data logging software, BenchLink, can communicate over either adapter so we have confirmed that connectivity is possible with either adapter.

0 Kudos
Message 6 of 13
(7,260 Views)

@Kwoo wrote:
SYStem:REMote is I think the command you want. See page 269 of the manual (I think).

I think you are correct, but I'm not clear on how to issue this command in my LabView program. I looked through the VIs in the instrument driver and couldn't find anything related to toggling the mode of the device.

When you open the messaging VIs, you should see usage of VISA Write. You can use the existing VIs to model a new VI you create using that as a command (SYS:REM). 

 

I don't recall if you need a leading : before the statement. Make sure to send the appropriate termination character - this might be specified in the initialization VI, in which case you'll see a property node labelled ASLR End Out. If this is there, do nothing extra. If this is not there, you probably need to manually append the termination character to the string that you wire to VISA Write. Again, the existing VIs should give some guidance.

 

This (http://digital.ni.com/public.nsf/allkb/862567530005F09C862565BE005AB500) is a link describing adding termination characters to every write. It's generally not recommended since it can make it less clear what's happening, but it might explain what you should look for if you don't see a character added in existing code.


GCentral
0 Kudos
Message 7 of 13
(7,256 Views)

Kwoo wrote:
 

The model we're using is an Agilent 34970A, the one without on-device USB or Ethernet connectivity. We're using an adapter to convert the GPIB connection in both cases. Agilent's data logging software, BenchLink, can communicate over either adapter so we have confirmed that connectivity is possible with either adapter.


Just a couple of points.  If you are checking that it works with the BenchLink software first, it may not be releasing the port for general use causing other attempts to communicate with the device to fail.  Are you able to see the device with NI-MAX before and after using BenchLink?  Also, make sure that the Ethernet and USB connections are not given the same name.  Next, are you using the Prologix GPIB-USB adapter?  If so, check here for details: https://forums.ni.com/t5/Example-Program-Drafts/Prologix-GPIB-USB-Controller/ta-p/3539152

Help the Community (and future reviewers) by marking posts as follows:
If it helped - KUDOS
If it answers the issue - SOLUTION
0 Kudos
Message 8 of 13
(7,131 Views)

The USB adapter is an Agilent 82357b. I can see the device in NI-Max and have tested with and without using BenchLink first. What happens with the USB is when the read command is executed in the lab-view program the Agilent beeps and then displays that there is an error. The error is error 550, which the manual indicates is:

Not able to execute command in local mode

The instrument has received a READ? or MEASure? command while in the local mode.
0 Kudos
Message 9 of 13
(7,126 Views)

@Kwoo wrote:

The USB adapter is an Agilent 82357b. I can see the device in NI-Max and have tested with and without using BenchLink first. What happens with the USB is when the read command is executed in the lab-view program the Agilent beeps and then displays that there is an error. The error is error 550, which the manual indicates is:

Not able to execute command in local mode

The instrument has received a READ? or MEASure? command while in the local mode.

That sounds like an issue with the USB adapter and not the Instrument.  The BenchLink software probably sends a command to the adapter to be the controller in charge; otherwise, it acts just like a bus listener.  It might be the same command set for an FTDI device in which you must send:

++mode 1

This will first set the USB to controller mode then try your normal SCPI commands. 

Help the Community (and future reviewers) by marking posts as follows:
If it helped - KUDOS
If it answers the issue - SOLUTION
0 Kudos
Message 10 of 13
(7,123 Views)