Ieee Command Group - Keithley 199 Instruction Manual

APPENDIX C
Table C-2. Hexadecimal and Decimal Command Table C-4. Typical Device-Dependent Command
Codes Sequence
Command
GTL
SDC
GET
LLO
DCL
SPE
SPD
LAG
TAG
SGG
UNL
UNT
Hex VaIue
01
04
08
11
14
18
19
2Q3F~
40-SF
60s
3F
5F
Decimal Value
1
4
8
25
32-63
64-95
96-127
tz
Typical Command Sequences
For the various multiline commands, a specific bus se-
quence 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 C-3 lists a typical bus sequence for ~sending an ad-
dressed multiline command. In this in&rice, the SDC
command is beiig sent to the instruinent. LIhX @ generally
sent as part of the sequence to ensure that no other active
listeners are present. Note that ATN is hue for both the
listen command and the SDC~&mmand byte itself.
Table C-3. Typical Addressed Command Sequence
*Assumes primary address = 26.
Table C-4 gives a typical device-dependent command se-
quence. In this instance, ATN is true while the instrument
is being addressed, but it is set high while sending the
device-dependent command string.
I I
I I
Data Bus I
ASCII Hex Decimal
1 UNL Set low ? 3F' 63
2 LAG* Stays low 3A 58
3 Data Set high x G 82
4 Data Stays high 48
5 DZti Stays high
::
58 88
*Assumes primary address = 26.
IEEE Command Groups
Command groups supported by the Model 199 are listed
in Table C-5. Device-dependent commands are not includ-
ed in this list.
stable C-5. IEEE Command Group
HANDSHAKES COMMAND GROUP
DAC= DATA AC-ED
RFD&READY FOR DATA
DAV= DATA VALID
UNIVERSAL COMMAND GROUP
ATN=ATIENTION
DCL=DEVICE CLEAR
IFC=INTERFACE CLEAR
LLO=I.QCAL LOCKOUT
REN=REMOTE ENABLE
SPD=SERIAL POLL~DISABLE
SPE=SERIAL POLL ENABLE
ADDRESS COMMAND GROUN
LISTEN: LAG=LISTEN ADDRESS GROUP
MLA=MY LISTEN ADDRESS
UNL=UNLISTEN
TALK: TAG=TALK ADDRESS~ GROUP
MZ%=MY TALK ADDRESS
uNT=uNTALK
OTA=Ol-HER TALK ADDRESS
ADDRESSED COMMAND GROUP
ACG=ADDRESSED COMMAND GROUP
GET=GROUP EXECUTE TRIGGER
GTL=GO 'ID LOCAL
SDC=SELECTIVE CLEAR
STATUS COMMAND GROUP
RQS=REQUEST SERVICE
SRQ=SERIAL POLL REQUEST
STB=STATUS BYTE
EOI=END
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