HP 53131A/132A 225 MHz Programming Manual page 93

Chapter 3 Programming Your Universal Counter for Remote Operation
Elements of SCPI Commands
A detailed description of each bit in the Standard Event Status Register follows:
Bit 0 (Operation Complete) is an event bit which is generated in response
to the *OPC command. This bit indicates that the Counter has completed
all pending operations.
If there are no pending operations at the time *OPC executes, this bit sets
immediately.
If there is a pending operation at the time *OPC executes, this event bit sets
when the pending operation condition transistions from TRUE to FALSE.
If
the :TRIGger:COUNt:AUTO is OFF, or
statistics are disabled, or
the function is set to Totalize or Voltage Peaks,
then the pending op eration condition is set TRUE when either: 1) a single
measurement is initiated, or 2) a continuous measurement cycle is initiated.
The pending operation condition is set FALSE when the measurement cycle
terminates.
If
the TRIGger:COUNt:AUTO is ON, and
statistics are enabled, and
the function is set to Totalize or Voltage Peaks,
then the pending operation condition is set TRUE when a block of
measurements is initiated. The pending operation condition is set FALSE
when the block of measurements completes; that is, when the last
measurement in the block completes.
Bit 1 is not used.
Bit 2 (Query Error) is an event bit which indicates that either 1) an
attempt was made to read the Output Queue when it was empty or 2) data
in the Output Queue has been lost.
Errors -400 through -499 are query errors.
Programming Guide 3-25