Ieee-488 Bus Command Summary - Keithley 7001 Instruction Manual

Table D-1

IEEE-488 bus command summary

Command
type Command
Uniline REN (Remote Enable)
EOI
IFC (Interface Clear)
ATN (Attention)
SRQ
Multiline
Universal LLO (Local Lockout)
DCL (Device Clear)
SPE (Serial Enable)
SPD (Serial Poll Disable)
Addressed SDC (Selective Device Clear)
GTL (Go To Local)
Unaddressed UNL (Unlisten)
UNT (Untalk)
Common —
SCPI —
Addressed multiline commands
Addressed commands are multiline commands that
must be preceded by the device listen address before
that instrument will respond to the command in ques-
tion. Note that only the addressed device will respond
to these commands. Both the commands and the ad-
dress preceding it are sent with ATN true.
SDC (Selective Device Clear) — The SDC command
performs essentially the same function as the DCL
command except that only the addressed device re-
sponds. Generally, instruments return to their power-
up default conditions when responding to the SDC
command.
GTL (Go To Local) — The GTL command is used to re-
move instruments from the remote mode. With some
instruments, GTL also unlocks front panel controls if
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State of
ATN
line Comments
X Set up devices for remote operation.
X Marks end of transmission.
X Clears interface.
Low Defines data bus contents.
X Controlled by external device.
Low Locks our local operation.
Low Returns device to default conditions.
Low Enables serial polling.
Low Disables serial polling.
Low Returns unit to default conditions.
Low Returns device to local.
Low Removes all listeners from the bus.
Low Removes any talkers from the bus.
High Programs IEEE-488.2 compatible instruments for
common operations.
High Programs SCPI compatible instruments for partic-
ular operations.
they were previously locked out with the LLO com-
mand.
GET (Group Execute Trigger) — The GET command is
used to trigger devices to perform a specific action that
depends on device configuration (for example, take a
reading). Although GET is an addressed command,
many devices respond to GET without addressing.
Address commands
Addressed commands include two primary command
groups and a secondary address group. ATN is true
when these commands are asserted. The commands in-
clude:
LAG (Listen Address Group) — These listen com-
mands are derived from an instrument's primary ad-
IEEE-488 Bus Overview
D-5