HP 16500C Programmer's Manual page 95

MSG - message
Indicates whether there is a message in the message queue (Not
implemented in the HP 16500C Logic Analysis System).
PON - power on
Indicates power has been turned on.
URQ - user request
Always returns a 0 from the HP 16500C Logic Analysis System.
CME - command error
Indicates whether the parser detected an error.
EXE - execution error
Indicates whether a parameter was out of range, or inconsistent with current
settings.
DDE - device specific error
Indicates whether the device was unable to complete an operation for device
dependent reasons.
QYE - query error
Indicates whether the protocol for queries has been violated.
The error numbers and strings for CME, EXE, DDE, and QYE can be read from a
device-defined queue (which is not part of IEEE 488.2) with the query
:SYSTEM:ERROR? STRING.
RQC - request control
Always returns a 0 from the HP 16500C Logic Analysis System.
OPC - operation complete
Indicates whether the device has completed all pending operations. OPC is
controlled by the *OPC common command. Because this command can
appear after any other command, it serves as a general-purpose operation
complete message generator.
Status Reporting
Bit Definitions
7–5