Figure 4-1. the model 187 status system, Remote interface reference, Scpi status system – American Magnetics 187 Self-Compensating Liquid Level Controller User Manual
Page 42
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Remote Interface Reference
SCPI Status System
A condition register continuously monitors the state of the instrument.
The bits of a condition register are updated in real time. A condition
register is read-only and is not cleared when you read the register. A query
of a condition register returns a decimal value in the appropriate output
buffer which corresponds to the binary-weighted sum of all bits set in the
register.
An event register latches various events. An event register is not buffered,
therefore once a bit is set, further occurrences of that event are ignored.
Once a bit is set in an event register, the bit remains set until the register
is read (
*ESR?
) or a
*CLS
(clear status) command is issued. A query of an
event register returns a decimal value in the appropriate output buffer
which corresponds to the binary-weighted sum of all bits set in the
register.
An enable register (or bitmask) defines which bits in an event register are
reported to the Status Byte register group. An enable register can be both
written and queried. The
*CLS
(clear status) command does not clear an
Fill Expired
0
1
2
3
4
5
6
7
<1>
<2>
<4>
<8>
<16>
<32>
N/A
<128>
*SRE <
value
>
*SRE?
Serial Poll
*STB?
C
EN
Summary Bit (RQS)
"OR"
Status Byte Registers
0
1
2
3
4
5
6
7
<1>
<2>
<4>
<8>
<16>
<32>
<64>
<128>
*ESE <
value
>
*ESE?
*ESR?
EV
EN
"OR"
Standard Event Registers
Operation Complete
Query Error
Device Error
Execution Error
Command Error
Power On
IEEE-488 Output Buffer
Serial Output Buffer
NOTES:
C = Condition Register
EV = Event Register
EN = Enable Register
0
1
2
3
4
5
6
7
<1>
<2>
<4>
<8>
<16>
<32>
<64>
<128>
STATus:ALARm:ENABle <
value
>
STATus:ALARm:ENABle?
STATus:ALARm:EVENt?
EV
EN
"OR"
Alarm Registers
HI Alarm
B Alarm
LO Alarm
RATE Alarm
A Alarm
0
1
2
3
4
5
6
7
C
Fill State
STATus:ALARm:COND?
Over/Under Flow
Max Dielectric
Exceeded
Figure 4-1. The Model 187 status system.