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IEEE-488 Bus Overview
D-7
Table D-2
Hexadecimal and decimal command codes
Command
Hex value
Decimal
value
GTL
SDC
GET
LLO
DCL
SPE
SPD
LAG
TAG
SCG
UNL
UNT
01
04
08
11
14
18
19
20-3F
40-5F
60-7F
3F
5F
1
4
8
17
20
24
25
32-63
64-95
96-127
63
95
Table D-3
Typical addressed command sequence
Table D-4
Typical common 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
?
;
EOT
3F
3B
04
63
59
4
*Assumes primary address = 27.
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
?
;
*
R
S
T
3F
3B
2A
52
53
54
63
59
42
82
83
84
*Assumes primary address = 27.