How to stop GPIB Instrument lock?

[DennonO]

Hi,

I am writting a program in Labview 8.5 that communicates through VISA (GPIB) with an Agilent 8960 E1963A. My issue is that as soon as the program makes its first command to the device, and indefinitely after, all the real instrument controls on the actual Agilent device cease to function. The only way to currently restore manual control is to completly disconnect the GPIB cable, or close every single NI application open (stopping the labview program is useless - labview in its entirety, even the welcome window, must be closed before control is restored). I have tried both clearing the buffers with the VISA CLEAR VI and closing the session after every VISA WRITE with a VISA CLOSE VI...alas to no avail. I'm still in the process of debugging, and it is extremely frustrating to open the program, run it, send one command, shut down and disconnect everything to make sure it worked, and then re open everything to try again with a second command...does anyone know how to fix this?

Thanks!!! 

[JÞB]

Hey Dennon

It sound like you need to put the Agilent test set on a diet.  Just press the button labled "LO-CAL" on the front of the unit and the "real" controls will start functioning again.

Most test equipments work about the same way.  When you initiallize remote control the front panel controls lock out to prevent accidental re-configuring of the unit from the front panel.  the local button will override the remote operation and restore manual control.

[PhillipBrooks · Accepted solution]

You can also use a function on the VISA Advanced palette named VISA GPIB Control REN

mode specifies the state of the REN line and optionally the device remote/local state. This input accepts the following values.

0	Deassert REN—Deassert REN line.
1	Assert REN—Assert REN line.
2	Go To Local; Deassert REN—Send the Go To Local (GTL) command and deassert REN line.
3	Assert REN; Address Device—Assert REN line and address device.
4	Local Lockout (Addressed Devices)—Send LLO to any devices that are addressed to listen.
5	Local Lockout (This Device)—Address this device and send it LLO, putting it in RWLS.
6	Go To Local—Send the Go To Local command (GTL) to this device.

[DennonO]

Thanks! Both work, but the VISA GPIB control REN was exactly what I was looking for!

Great to see such quick, accurate support. 

[Isalanlin]

Hi  Phillip,

I have some problems with this VISA GPIB control REN function,

the picture below is how I connected to my instrument, However, it failed.

May you give me some advice on how to solve this REN problem?

Many thanks.

[JÞB]

---

@Isalanlin wrote:

Hi  Phillip,

I have some problems with this VISA GPIB control REN function,

the picture below is how I connected to my instrument, However, it failed.

May you give me some advice on how to solve this REN problem?

Many thanks.

---

Well, usually posting to a decade old thread without giving specific information about how [your code] failed isn't going to help us help you.

What did you want your code to do?

[cstorey]

Maybe Open the VISA session first, then assert Remote?  We would need the error info at the very least to help further.  After that the instrument make/model would help.

[JÞB]

---

@cstorey wrote:

Maybe Open the VISA session first, then assert Remote?  We would need the error info at the very least to help further.  After that the instrument make/model would help.

---

Nothing will override "the diet button,"  you know, the button on the equipment that is labled LoCal.