Agilent / HP / Keysight E2071C

This GPIB interface is capable of very fast performance.

On rare occasions, some slower instruments have exhibited problems when connected to these high speed interfaces.

This high speed interface may generate bus events so closely spaced that a slow instrument's processor can be overrun and lose track of the current bus state.

When this happens, the instrument may indicate an error, or it may simply stop handshaking in the middle of a transaction.

In effect, you need to turn this unit into a traditional unbuffered interface.