programmatically check if instrument is connected

[Stephen.E]

I'm trying to modify a program to enable/disable certain parts depending on whether or not the instrument it controls is connected via GPIB.  There is limited functionality of the program that I still want to use even if the instrument isn't actually connected and turned on.  Is there a way to check the GPIB connection programmatically that won't throw out all kinds of run time errors if it isn't connected?

[Dennis_Knutson]

You can query the instrument. The only thing that will happen is a timeout if it's not connected. You can easily trap that that error.

[Tavar]

You can use the Visa Find Resource Function to get a list of GPIB actively connected to the computer. Then you can send an *IDN? query to each and match it against a list of known instruments to check if the required instrument is connected and communicating.

[AnkitG]

I used something like this(see attached ) to check my lock-in communication which uses GPIB connection.

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@Stephen.E wrote:

I'm trying to modify a program to enable/disable certain parts depending on whether or not the instrument it controls is connected via GPIB.  There is limited functionality of the program that I still want to use even if the instrument isn't actually connected and turned on.  Is there a way to check the GPIB connection programmatically that won't throw out all kinds of run time errors if it isn't connected?

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[Stephen.E]

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@Tavar wrote:

You can use the Visa Find Resource Function to get a list of GPIB actively connected to the computer. Then you can send an *IDN? query to each and match it against a list of known instruments to check if the required instrument is connected and communicating.

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Thanks, I'll give this a shot.

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@AnkitG wrote:

I used something like this(see attached ) to check my lock-in communication which uses GPIB connection.

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 I'm not familiar by sight with all of the commands you used.  Would you mind uploading the .vi file?  Thanks.

[AnkitG]

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@Stephen.E wrote:

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@Tavar wrote:

You can use the Visa Find Resource Function to get a list of GPIB actively connected to the computer. Then you can send an *IDN? query to each and match it against a list of known instruments to check if the required instrument is connected and communicating.

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Thanks, I'll give this a shot.

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@AnkitG wrote:

I used something like this(see attached ) to check my lock-in communication which uses GPIB connection.

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 I'm not familiar by sight with all of the commands you used.  Would you mind uploading the .vi file?  Thanks.

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Those are just visa write , read function and then I am converting decimal to numbers and numbers to boolean to check the status.

[Dennis_Knutson]

The image shows code that is pretty specific to a certain instrument. In all of the suggestions, you will get the timeout rror that I mentioned.

[Dennis_Knutson]

Can't edit my post.

You'll actually get an error on a write because of the lack of handshaking.

[Stephen.E]

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@Dennis_Knutson wrote:
Can't edit my post.

You'll actually get an error on a write because of the lack of handshaking.

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I'm not entirely sure if I understand what you are saying or not.  Let me talk my way through it and see if it sounds correct.  Are you saying that I could use a visa write, then just unbundle the status bolean from the error and that will essentially tell me if the instrument is connected or not?  Failing the visa write wont cause any runtime error messages to pop up?

[crossrulz]

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@Stephen.E wrote:

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@Dennis_Knutson wrote:
Can't edit my post.

You'll actually get an error on a write because of the lack of handshaking.

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I'm not entirely sure if I understand what you are saying or not.  Let me talk my way through it and see if it sounds correct.  Are you saying that I could use a visa write, then just unbundle the status bolean from the error and that will essentially tell me if the instrument is connected or not?  Failing the visa write wont cause any runtime error messages to pop up?

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If you handle the error and clear it, there won't be a pop up.  But your are correct.  If there is an error from the VISA write, your instrument is not there.  You can just unbundle the status boolean.