EXFO FVA-3150 Variable Attenuator - Manual (Page 81)

Remote Control Commands
Variable Attenuator 75
IEEE 488.2 Required Commands
*SRE
Description This command sets bits in the Service Request Enable Register
(default value is 255) and enables the corresponding bit in the
Status Register. The command can be used to select which
events can initiate a service request.
Syntax *SRE
Parameter The parameter must be between 0 and 255.
*SRE?
Description This query returns the contents of the Service Request Enable
Register.
Syntax *SRE?
Response Binary integer between 0 and 255.
*STB?
Description This query returns the contents of the Status Byte Register.
Syntax *STB?
Response A binary integer between 0 and 255.
Note The STB? command is equivalent to the *STB? command. Both
give the same result.