Uniline Commands - Keithley 2182 User Manual

Table F-1
IEEE-488 bus command summary
Command
type Command
Uniline REN (Remote Enable)
EOI
IFC (Interface Clear)
ATN (Attention)
SRQ
Multiline LLO (Local Lockout)
Universal 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 —

Uniline commands

ATN, IFC and REN are asserted only by the controller. SRQ is asserted by an external device.
EOI may be asserted either by the controller or other devices depending on the direction of data
transfer. The following is a description of each command. Each command is sent by setting the
corresponding bus line true.
REN (Remote Enable) — REN is sent to set up instruments on the bus for remote operation.
When REN is true, devices will be removed from the local mode. Depending on device
configuration, all front panel controls except the LOCAL button (if the device is so equipped)
may be locked out when REN is true. Generally, REN should be sent before attempting to
program instruments over the bus.
EOI (End or Identify) — EOI is used to positively identify the last byte in a multi-byte
transfer sequence, thus allowing data words of various lengths to be transmitted easily.
IFC (Interface Clear) — IFC is used to clear the interface and return all devices to the talker
and listener idle states.
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 out 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
particular operations.
IEEE-488 Bus Overview F-7