User`s guide

6-15
Status Reporting
Output Queue
Output Queue
The output queue stores the oscilloscope-to-controller responses that are
generated by certain instrument commands and queries. The output queue
generates the Message Available summary bit when the output queue contains
one or more bytes. This summary bit sets the MAV bit (bit 4) in the Status Byte
Register.
The output queue may be read with the HP Basic ENTER statement.
Message Queue
The message queue contains the text of the last message written to the advisory
line on the screen of the oscilloscope. The length of the oscilloscope’s message
queue is 1. The queue is read with the SYSTEM:DSP? query. Note that messages
sent with the SYSTem:DSP command do not set the MSG status bit in the Status
Byte Register.
Clearing Registers and Queues
The *CLS common command clears all event registers and all queues except
the output queue. If *CLS is sent immediately following a program message
terminator, the output queue is also cleared.