Error And Output Queues - Keysight Technologies N6705C Operating And Service Manual

7 SCPI Programming Reference
Bit Bit Name
6 Master Status Summary
7 Operation Status Sum-
mary
MSS and RQS Bits
MSS is a real-time (unlatched) summary of all Status Byte register bits that are enabled by the Service
Request Enable register. MSS is set whenever the instrument has one or more reasons for requesting
service. *STB? reads the MSS in bit position 6 of the response but does not clear any of the bits in the
Status Byte register.
The RQS bit is a latched version of the MSS bit. Whenever the instrument requests service, it sets the
SRQ interrupt line true and latches RQS into bit 6 of the Status Byte register. When the controller does
a serial poll, RQS is cleared inside the register and returned in bit position 6 of the response. The
remaining bits of the Status Byte register are not disturbed.

Error and Output Queues

The Error Queue is a first-in, first-out (FIFO) data register that stores numerical and textual description
of an error or event. Error messages are stored until they are read with
overflows, the last error/event in the queue is replaced with error -350,"Queue overflow".
The Output Queue is a first-in, first-out (FIFO) data register that stores instrument-to-controller
messages until the controller reads them. Whenever the queue holds messages, it sets the MAV bit
(4) of the Status Byte register.
352
Decimal
Value
64 One or more bits are set in the Status Byte Register and may generate a Service
Request. Bits must be enabled, see *SRE.
128 One or more bits are set in the Operation Status Register. Bits must be enabled, see
STATus:OPERation:ENABle.
Definition
SYSTem:ERRor? If the queue
Keysight N6705C Operating and Service Guide