High speed 488 controller with normal (older) instrument

[RLD]

When using a GPIB board which supports high speed 488 to control an "normal speed 488" instrument is it possible to force the board to only run in normal speed 488 mode?

Or is there nothing to worry about when talking to an older pre-HS488 type instrument with a "modern" HS488 controller board?

[Dennis_Knutson]

I have yet to use a HS488 compatible instrument (they're kind of rare) and have no problems with standard instruments.

[RLD]

So it's safe to assume that a HS-488 GPIB board won't send out any signal that an older pre-HS instrument might misinterpret and respond in an unexpected manner? 

[Dennis_Knutson]

Yes.

[GPIB_Guru]

The extra command bytes that are sent out during the IEEE 488.1-2003 non-interlocked handshake transfers (HS-488) should not affect any instruments. However, to be extra safe, NI requires that HS488 be enabled before it sends out any new commands. If you don't enable HS488, the board will operate in a mode that is 100% compatible with prior IEEE 488.1 standards. FYI, to enable HS488, you change the HS cable length to a non-zero value.