Confirm operation of HS488 using LabVIEW

[Placebo]

Hi,

I need to confirm if an instrument I've connected to has correctly implemented HS488.

Is there a way of verifying this using LabVIEW ?

Many thanks,

[mikeporter]

You can use the IDN command to get the identifier for the instrument, but beyond that I don't know. The HS488 mode selection is automatically done at the chip level.

Mike...

[Placebo]

Yes, I can see that, thank you.

The possibility also exists that an instrument has been incorrectly labeled as HS488 compliant when it isn't. I was wondering if this particular "failure" could be detected by sending the cable length. Hopefully, a non-compliant instrument would fail to process the instruction, but I'm not sure if this is true.

[Josh_E]

Hi Placebo,

Am I correct in saying that any non HS488 compliant instrument would not be able to process any HS488 command?

If so, can you just use that to determine whether the instrument is compliant or not?

Kind regards,

[mikeporter]

Unless things have changed, HS488 simply effects how the instrument handles handshaking of long data transfers and so there are no "HS488 commands" as such.

Instead, during an initial phase of the handshaking process, the HS488 controller chip twiddles the interface lines in a way that will not messup a non-HS488 chip, but which will cause another HS488 chip to respond in a particular way. When the chip that initiated the interaction sees that response it knows that the other device is capable of doing an HS488 data transfer and so proceeds on that basis.

Mike...

[Placebo]

Hi Josh,

I believe the non-compliant instrument will still process an IEEE compliant command, what I'm hoping is that it will fail with a specific HS488 instruction such as the length of the cable, but I have a feeling this would be too simple.

I guess I need an instrument that I know for certain is not HS488 compliant and send the cable length to see what happens.

The best outcome would be to determine if an instrument is compliant programatically with LabVIEW, but if this is not possible then I'd appreciate another strategy.

[Josh_E]

Hi Placebo,

You could try to use VISA write to send a specific HS488 command, and then see if an error occurs. If the error pertains to some invalid parameter, then it could be used to figure out whether the instrument is HS488 compliant or not.

The error you might expect could be −1073807240 (The value of some parameter (which parameter is not known) is invalid.) or 1073807239 (The protocol specified is invalid).

As you said, you's ideally need to test this on an instrument that is not compliant with HS488.

Unfortunately I'm not aware of any explicit way to do this in LabVIEW.

Let me know your thoughts.

Kind regards,