5.4 Service Request and Status Byte
CA5350
5-8
5.4 Service Request and Status Byte
5.4.1 Service Request
Service Request (
SRQ
) is the function for setting the signal wire of
SRQ
of bus line to
Low (=True) and allocating it to controller when issue of
SRQ
is permitted and
CA5350
is in the following states.
When input or output over is detected
When a front panel key is pressed
When ready for receiving the next command
When an error has occurred
When controller detects
SRQ
of
CA5350
and conducts serial polling,
CA5350
will
transfer the status byte of
“5.4.2 Status Byte”
to the controller, and withdraw
SRQ
.
SRQ
can be issued when its issue is permitted irrespective of the remote/local state.
5.4.2 Status Byte
Status Byte of
CA5350
is as shown in
“Table 5-2 Status Byte”
.
Table 5-2 Status Byte
Bit
Contents
Conditions for set
“1”
Conditions for reset
“0”
(MSB)7 0
(Not used) 0 always
6
RQS
When
SRQ
is sent
*1
When
DCL
or
SDC
is
received
After reading the status byte
5
Occurrence
of error
When an error has occurred
After reading the error
status
*2
4
Ready
for
receiving
commands
When ready for receiving the
next command
When the an command is
received
*3
3
0
(Not used) Always
0
2
0
(Not used) Always
0
1
Key
operation
When a key of the front
panel is operated
After output of device
information
*4
(LSB)0 Over input
detection
When input over is detected
When input over is no longer
detected
*1: Only for GPIB. There is no
SRQ
for USB.
*2: After the output of response message of the "
U1
" command
*3: When "
X
" command is received
*4: After the output of response message of the "
U0
" command
