Local Mode

[Dennis_Knutson]

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Sean Wint wrote:

I am using GPIB by the way. I currently am using the VISA Write VI to send commands to instrument. The two commands found in the manual used to send the device into local mode are LLO (Local Lockout) and GTL (Go To Local). These are listed under Local Addresses. I try to send these commands, but an error occurs.

Sean

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How are you sending those commands. Doing a GPIB Write or VISA Write of those is NOT correct. Did you try the dedicated functions I mentioned? If you did and got an error, what was the error.

[Sean Wint]

Yeah, I see that as well. If you look on page 113, there is a list of commands for GPIB. The Common commands work with no problem when I write them to a VISA. The address commands are what returns errors. Do you think that becuase GPIB can comunicate to multiples devides through one controller, that the address of the instrument you (the programmer) are trying to communicate with must be attached alongside the command?

Sean

[Sean Wint]

I was sending those commands using a VISA Write. Let me try what you mentioned and see what comes up.

[Ray.R]

Although it was mentionned earlier, it is worth mentioning again.

Try using MAX to see how the instrument responds to the command(s).

Go into Devices & Interfaces, select the GPIB that is connected to the instrument, select the instrument within the list and click on Communicate with Instrument.

You can try the command from that interface.

R

[Sean Wint]

Oh, it responds well with MAX. I don't have a problem interfaciing with the instrument through MAX. The command used to send the Power Supply into Local Mode is "ibloc". The question at hand is how to do this through LabVIEW.

[Ray.R]

Have you implemented a routine to communicate with your instrument?  If so, you can use the same one.

R

[Ray.R]

See attached code

R

[lmtis]

Sean,

the fact that the command works with MAX is a HUGE piece of information. How about you post a screen capture of IMax right before you send a successful command send to put the PS into LOC MODE.  Also post the LV code that you use that does not work.

[Ray.R]

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lmtis wrote:
Also post the LV code that you use that does not work.

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Oop.ss..   I misread the post... reading too quickly..

Message Edited by JoeLabView on 07-09-2008 09:15 PM

[Dennis_Knutson]

For those that have never programmed GPIB with anything other than LabVIEW, ibloc is a function in the NI-488 driver. It is not a command passed to an instrument with a write. The ibloc issues a GTL (Go to Local) which is one of the Multiline Interface Messages defined by IEEE-488. The GTL message controls the state of one of the control lines (REN) in the GPIB interface. The GTL in LabVIEW is issued by the functions I already mentioned or with forgotten two other methods I had forgotten about. On the GPIB palette, there is the GPIB Misc function. With a string of 'loc address', the GTL command will be issued. The equivalent function on the VISA palette is the VISA GPIB Command. With this, I think you just have to write GTL.