2 scpi status system, Figure 4-1. the model 420 status system, Scpi status system – American Magnetics 420 Power Supply Programmer User Manual
Page 88: Figure 4-1, The model 420 status system, Remote interface reference, Rev. 7
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Remote Interface Reference
SCPI Status System
Many commands also require multiple keywords to traverse the tree
structure of the entire Model 420 command set. For example, commands
associated with a current setting require the prefix of
CONFigure:CURRent
. Note that a colon (
:
) separates the keywords. No
spaces are allowed before or after the colon. Parameters must be separated
from the command keyword(s) by at least one space.
4.2.2
SCPI Status System
The Model 420 status system reports various conditions of the instrument
in two registers groups shown in Figure 4-1. The register groups consist of
a condition or event register, and an enable register which controls the
actions of specific bits within the condition or event registers.
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
0
0
1
1
2
2
3
3
4
4
5
5
6
6
7
7
<1>
<1>
<2>
<2>
<4>
<4>
<8>
<8>
<16>
<16>
<32>
<32>
N/A
N/A
<128>
<128>
*SRE <
value
>
*SRE?
Serial Poll
*STB?
C
EN
Summary Bit (RQS)
"OR"
Status Byte Register
0
0
1
1
2
2
3
3
4
4
5
5
6
6
7
7
<1>
<1>
<2>
<2>
<4>
<4>
<8>
<8>
<16>
<16>
<32>
<32>
<64>
<64>
<128>
<128>
*ESE <
value
>
*ESE?
*ESR?
EV
EN
"OR"
Standard Event Register
Operation Complete
Query Error
Device Error
Execution Error
Command Error
Power On
Quench Condition
IEEE-488 Output Buffer
Serial Output Buffer
NOTES:
C = Condition Register
EV = Event Register
EN = Enable Register
Figure 4-1. The Model 420 status system.