How do I go from Local Lockout to Local

[dantheman]

How do I place a device that is in Local Lockout mode (by way of ibllo()) to Local mode?

[GPIB_Guru]

Deassert the REN line (ibsre 0). Once the REN line is deasserted, all devices must enter Local state within t4 (< 100 uS).

Unfortunately, you cannot just set a single device back into local state once you have placed it into a lockout state.

[Andband]

How exactly does sending this command work with Labview?

I tried a GPIB Write with the datastring "ibsre 0". But this didn't work.  

The thing is, I want to avoid using VISA because I don't understand the actual purpose (or better the difference to GPIB-commands itself) of it and all my other commands I use in my program are just ordinary GPIB commands (I mean commands issued with Labview's GPIB-Write).So I actually don't want to mix it up.

Is there a way to go back to local without using VISA at the end of my program? 

Message Edited by Andband on 02-15-2010 01:06 PM

[smercurio_fc]

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Andband wrote:

How exactly does sending this command work with Labview?

I tried a GPIB Write with the datastring "ibsre 0". But this didn't work. 

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And it won't. GPIB Write is for sending commands to instruments, not for performing bus/instrument non-command operations, such as REN. To do this using VISA you would use VISA GPIB Control REN Function. To do this using the regular GPIB functions you could use GPIB Misc. Alternatively you could use EnableLocal, but you'd have to wire an empty array for the instrument list to get just REN deasserted. 

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The thing is, I want to avoid using VISA because I don't understand the actual purpose (or better the difference to GPIB-commands itself) of it and all my other commands I use in my program are just ordinary GPIB commands (I mean commands issued with Labview's GPIB-Write).So I actually don't want to mix it up.

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For an overview of VISA you should look at NI-VISA Overview.

[Andband]

GPIB enable works perfect.

Thank you also for your explanations.

But I don't know why you claim that I have to wire anything, though. The documentation says, if nothing's wired, all instruments on the bus will go back to local mode - and that seems to work.

[smercurio_fc]

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Andband wrote:

But I don't know why you claim that I have to wire anything, though. The documentation says, if nothing's wired, all instruments on the bus will go back to local mode - and that seems to work.

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I wasn't telling you anything different from what the help file says. If you wire in an array with a list of instrument addresses, then only those addresses will receive the Go To Local command. If you leave the input disconnected, then the GPIB REN line is deasserted, which means all instruments will go to local. The REN line is an interface-level line, not an instrument-level setting. Thus, if you explicitly wanted to deassert REN rather than telling a specific instrument to go to local, with the EnableLocal function you'd have to leave the address list input unwired. Alternatively, you could use the GPIB Misc function which is a little more explicit.

Likewise, to assert REN you could use the EnableRemote function with the address list input unwired. This again means that all instruments on the bus will be in remote. 

[Andband]

Ah, ok. In my case it doesnt make any difference then (at least I think that), because I am only using one instrument on the bus. Hence asserting or deasserting REN means some kind of global broadcast for the whole bus. I hope I got that right now.

[smercurio_fc]

That's essentially correct. Since you have only one instrument on your bus the difference is non-existent in your case.