Fluke 6105A - IEEE 488 and SCPI Standard Defined Features; Status Summary Information and SRQ

6100B/6105A
Users Manual
5-12
5-25. IEEE 488 and SCPI Standard Defined Features
SCPI Status Structure Registers
bit 7
OSS
bit 5
ESB
bit 4
MAV
bit 3
QSS
bit 2
bit 1
bit 0
MSS RQS
bit 6
Status Byte
Register
bit 7
PON
bit 5
CME
bit 4
EXE
bit 3
DDE
bit 2
QYE
bit 1
RQC
bit 0
OPC
Standard-
Defined
Event Status
Register
bit 6
URQ
Summary Bit — ESB
Event Status
Enable Register
Service Request
Enable Register
STB? SRE?
SRE
phs Nrf
ESR? ESE?
ESE
phs Nrf
Output
Queue
FIFO
Message Available Bit — MAV
(True if one or more
messages are present in
the Output Queue)
Questionable
Status
Register
Summary Bit — QSS
Questionable
Status
Enable Register
bit 15
bit 11
bit 9
bit 7
bit 5
bit 3
bit 1
Operation
Status
Register
bit 13
Summary Bit — OSS
Operation Status
Enable Register
OPERation:
ENABle ?
OPERation:
ENABle <DNPD>
Power On
Command Error
Execution Error
Device-Dependent Error
Query Error
Operation Complete
bit 14
bit 10
bit 8
bit 6
bit 4
bit 2
bit 0
bit 12
OPERation:
EVENt ?
QUEStionable:
ENABle ?
QUEStionable:
ENABle <DNPD>
QUEStionable:
EVENt ?
bit 15
bit 11
bit 9
bit 7
bit 5
bit 3
bit 1
bit 13
bit 14
bit 10
bit 8
bit 6
bit 4
bit 2
bit 0
bit 12
IEEE 488.2 Status Structure Registers
Master Status Summary Bit
Request for Service Bit
**
*
*
*
*
gdw55.eps
Figure 5-2. IEEE 488 and SCPI Standard Defined Features
5-26. Status Summary Information and SRQ
The Status Byte consists of four summary bits which notify events in the 8-bit latched IEEE
488.2 defined Event Status Register (ESB), the two 16-bit latched SCPI defined registers
(OSS & QSS), and the Output Queue (MAV). Whenever one of these summary bits is
enabled and set true, the Status Byte summary bit (MSS) is also set true. The buffered bit
RQS follows true when MSS goes true, and will set the IEEE 488 SRQ line true (Note that
in the diagram above no arrow points at bit 6 of the Service Request Enable Register - bit 6
is always enabled).
A subsequent serial poll by the Application Program will discover that the instrument was
the requesting device (while resetting RQS false again, MSS remaining true), and which of
the summary bits is true. The *STB? command is an equivalent command to serial poll,
where serial poll is not available.