EXFO FTB-2 - Manual (Page 365)

IEEE 488.2 and Specific Command Reference
FTB-2 and FTB-2 Pro 355
IEEE 488.2 Required Commands
Response(s) RegisterValue:
The response data syntax for <RegisterValue> is
defined as a <NR1 NUMERIC RESPONSE DATA>
element.
The <RegisterValue> ranges from 0 through 255.
When converted to binary (base 2), the
<RegisterValue> represents the current bit
values of the Service Request Enable Register.
Example(s) *SRE returns 32 (bit ESB)
See Also *SRE
*STB?
*SRE?