:OPERation[:EVENt]? STATus:OPERation[:EVENt]? queries the status of the Standard Operation Status Event Register.
Comments ∙ Output Format: Returns a decimal weighted value from 0 to 256 indicating which bits are set true.
∙Related Commands: [ROUTe:]SCAN
Example Reading the Operation Status Event Register after a Scanning Cycle
STAT:OPER? | Returns the bit values of the  | 
  | Standard Operation Status Event  | 
  | Register. Returns +256 if bit 8 is  | 
  | set to 1; +0 if bit 8 is set to 0.  | 
64 HP E1368A/69A/70A Command Reference | Chapter 4  |