Anritsu MT9812B, Руководство по эксплуатации, Страница: 95 / 144

5-27
Remote Control
5
5.5.2 Device Dependent Summary Message
IEEE 488.2 does not define whether status register bit 7 (DIO 8) and bit 3 (DIO 4)
to bit 0 (DIO 1) are used as status register summary bits or the bits indicating
existence of data in the queue. Accordingly, these bits can be used as device
dependent summary message bits.
Device dependent summary messages have a register model or queue model sta-
tus data structure. This status register is a pair of registers used to report events
and states in parallel or a queue used to report states and information sequentially.
The summary bit provides a summary of the current status of the corresponding
status data structure. For the register model, the summary message bit becomes
True when one or more events have become True with occurrence of events en-
abled. For the queue model, the summary message bit becomes True when the
queue is not empty.
In the MT9810A, bit 1 and bit 0 are unused, and bits 3 and 7 are used as summary
bits of the status register; bit 2 is allocated to the queue as shown in the following
diagram. Therefore, there are four types (two types for extension) of register
models and there are two types (one type for extension) of queue models.
7
ESB
MAV
3
2
1
0
MSS 6 RQS
Standard event
register
Status summary
message
Status Byte Register
……
Output Queue
Extended event
register or queue
Extended event
register or queue
Extended event
register or queue
Extended event
register or queue
Extended event
register or queue
(Queue is not used)
(Queue is not used)
(Not used)
(Not used)
(Not used)
Service request
occurrence
Data Data Data Data Data
5.5 Status Byte Registe