Agilent Technologies 8712ET Programmer's Manual page 59

Using Status Registers
The Analyzer's Status Register Sets
The commands used to read and write to the Status Byte registers are
listed below:
an IBASIC (or HP BASIC) command used in the
SPOLL
service request process to determine which device on
the bus is requesting service.
reads the value of the instrument's status byte. This is
*STB?
a non-destructive read—the Status Byte is cleared by
the *CLS command.
sets bits in the Service Request Enable register. The
*SRE <num>
current setting of the Service Request Enable register
is stored in non-volatile memory. If *PSC has been set,
it will be saved at power on.
reads the current state of the Service Request Enable
*SRE?
register.
5-14 Programmer's Guide