EXFO FVA-3150 Variable Attenuator - Manual (Page 55)

Controlling Your Variable Attenuator Remotely
Variable Attenuator 49
Standard Status Data Structure
Standard Status Data Structure
The following page illustrates the four common status and enable registers
as defined by IEEE 488.2. This diagram is a useful aid in understanding the
general commands and how a service request (SRQ) is generated. The
four registers are:

Standard Event Status Register (ESR)

Standard Event Status Enable Register (ESE)

Status Byte Register (STB)

Service Request Enable Register (SRE)
Bit ESR ESE STB SRE
0 Operation
Complete
Operation
Complete
Source Status Source Status
1 Request Control Request Control
2 Query Error Query Error Error Bit
3 Device-
Dependent Error
Device-
Dependent Error
Questionable
Status
Questionable
Status
4 Execution Error Execution Error Event Status Bit Event Status Bit
5 Command Error Command Error Message
Available
Message
Available
6 User Request User Request Master Summary
Status
Request
Service/Master
Summary Status
7 Power On Power On Operation Status Operation Status