Keithley 2700 User Manual

G-8 IEEE-488 Bus Overview Model 2700 Multimeter/Switch System User’s Manual
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.
ATN (Attention) — The controller sends ATN while transmitting addresses or multiline
commands.
SRQ (Service Request) — SRQ is asserted by a device when it requires service from a
controller.
Universal multiline commands
Universal commands are those multiline commands that require no addressing. All
devices equipped to implement such commands will do so simultaneously when the com
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mands are transmitted. As with all multiline commands, these commands are transmitted
with ATN true.
LLO (Local Lockout) — LLO is sent to the instrument to lock out the LOCAL key and all
their front panel controls.
DCL (Device Clear) — DCL is used to return instruments to some default state.
Instruments usually return to their power-up conditions.
SPE (Serial Poll Enable) — SPE is the first step in the serial polling sequence which is
used to determine which device has requested service.
SPD (Serial Poll Disable) — SPD is used by the controller to remove all devices on the
bus from the serial poll mode and is generally the last command in the serial polling
sequence.

Keithley 2700 Specifications

General

Type	Digital Multimeter
Measurement Functions	DC Voltage, AC Voltage, DC Current, AC Current, Resistance, Frequency, Temperature
DC Voltage Range	100 mV to 1000 V
AC Voltage Range	100 mV to 750 V
Frequency Range	3 Hz to 500 kHz
Temperature Range	-200°C to +1372°C
Display	Vacuum Fluorescent Display
Connectivity	IEEE-488, RS-232
Channels	10
Power Supply	100V to 240V AC, 45Hz to 66Hz
DC Current Range	10 µA to 3 A
AC Current Range	10 µA to 3 A
Temperature Measurement	Thermocouple, RTD