Keithley 6430, Инструкция по эксплуатации

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D-12 IEEE-488 Bus Overview
Typical command sequences
For the various multiline commands, a speci fi c bus sequence must take place to properly
send the command. In particular, the correct listen address must be sent to the instrument
before it will respond to addressed commands. Table D-3 lists a typical bus sequence for send-
ing the addressed multiline commands. In this instance, the SDC command is being sent to the
instrument. UNL is generally sent as part of the sequence to ensure that no other active listeners
are present. Note that ATN is true for both the listen command and the SDC command byte
itself.
Table D-4 gives a typical common command sequence. In this instance, ATN is true while
the instrument is being addressed, but it is set high while sending the common command string.
Table D-3
Typical addressed multiline command sequence
Step Command ATN state
Data bus
ASCII Hex Decimal
1
2
3
4 UNL
LAG*
SDC Set low
Stays low
Stays low
Returns high ?
8
EOT
3F
38
04 63
56
4
*Assumes primary address = 24.
Table D-4
Typical addressed common command sequence
Step Command ATN state
Data bus
ASCII Hex Decimal
1
2
3
4
5
6 UNL
LAG*
Data
Data
Data
Data Set low
Stays low
Set high
Stays high
Stays high
Stays high ?
8
*
R
S
T
3F
38
2A
52
53
54
63
56
42
82
83
84
*Assumes primary address = 24.