EXFO FLS-2200 Broadband Source - Manual (Page 47)

Using Your Broadband Source in an Automated Test Environment
Broadband Source 39
Standard Status Data Structure
Standard Status Data Structure
Each device that is physically connected to the GPIB bus has four status
registers with a structure complying with the IEEE 488.2 standard. These
registers allow the controller to monitor events and get useful information
on the status of the devices it controls.

Standard Event Status Register (ESR)
Bits Mnemonics Bit Value
7 Power On 128
6 Not used 0
5 Command Error 32
4 Execution Error 16
3 Device Dependent Error 8
2 Query Error 4
1 Not used 0
0 Operation Complete 1