Anritsu MT8801C - Device-Dependent Summary Messages

Section 5 Status Messages
5-6
5.2.2 Device-dependent summary messages
The IEEE488.2 standard specifies that bits 7 (DIO8) and 3 (DIO4) to 0 (DIO1) of the
status byte register can be used as status register summary bits, or to indicate that there
is data in a queue.
Device-dependent summary messages have the respective status data structures of the
register model or the queue model. Thus, the status data structure may be either the
register to report events and status in parallel or the queue to report conditions and
status in sequence. The summary bit represents a summary of the current status of the
corresponding status data structure. For the register model, the summary message is
true when there is an event set to permit the occurrence of more than one true event;
while for the queue model, it is true if the queue is not empty.
As shown below, the MT8801C does not use bits 0, 1 and 7. As it uses bits 2 and 3 as
the summary bit of the status register, it has 3 register model types (where 2 types are
extended) and one queue model type (with no extension).
ESB
MAV
ERR
END
Service Request generated
Status byte register
Status summary
message
Standard event
status register
Extended event
register or queue
......Output queue
(Queue not used)
(Not used)
(Not used)
(Queue not used)
MSS RQS
7
6
5
4
3
2
1
0
Bit
Data Data Data Data
Extended event
register or queue
Extended event
register or queue
Extended event
register or queue