User`s manual

The Service Request
Enable Register
The Service Request Enable Register specifies which (status group)
summary bit(s) will send a service request message to the computer over
GPIB. The bits are specified (unmasked) with the command:
*SRE <unmask>
All unmasked bits in the Enable Register can be determined with the command:
*SRE?
The Service Request Enable Register is cleared at power-on, or by
specifying an
<unmask> value of 0.
Presetting the Enable
Register and Transition
Filter
The Enable Registers and Transition Filters in the Questionable Signal and
Operation Status Groups can be preset (initialized) with the command:
STATus:PRESet
All bits in the Enable Registers are masked (i.e. <unmask> is 0), and all bits
in the Condition Registers set corresponding bits in the Event Registers on
positive (0 to 1) transitions.
Chapter 9 AFG Status 443