Keithley 2701 User Manual

Model 2701 User’s Manual Scanning 7-7
STEP operation overview — When the STEP key is pressed, the Model 2701 leaves the
idle state, closes the first channel, and waits for the programmed trigger event. After the
trigger is detected, the instrument may be subjected to one or more delays before
performing the measurement.
After a reading is taken and stored in the buffer, the Model 2701 outputs a trigger pulse,
opens the closed channel, and then closes the next channel in the scan list. The instrument
then waits for another trigger event to measure the channel. After the last channel is
scanned, the instrument returns to the idle state with the first channel in the scan list
closed.
SCAN operation overview — When the SCAN key is pressed, the Model 2701 leaves the
idle state, closes the first channel, and waits for the programmed trigger event. After the
trigger is detected, the instrument may be subjected to one or more delays before
performing the measurement.
After a reading is taken and stored in the buffer, the Model 2701 opens the closed channel
and then closes the next channel in the scan list. Operation keeps looping around to
measure all channels in the scan list. After the last channel in the scan list is measured, the
Model 2701 outputs a trigger pulse.
If programmed to again scan the channels in the scan list, the Model 2701 will wait at the
control source for another trigger event. After all the scan list channels are again
measured, the Model 2701 will output another trigger pulse. After all programmed scans
are completed, the instrument returns to the idle state with the first channel in the scan list
closed.
The individual components of the trigger models are explained as follows:
Idle
When a scan is enabled (STEP or SCAN annunciator on), operation goes into the idle state
and immediately drops down to the control source. Note that after the last channel in the
scan is measured, operation returns to the idle state, where measurements are halted and
the first channel in the list is closed.
Control sources
For front panel operation, there are three control sources to manage the scan: Immediate,
Timer, and External Trigger. Operation is held up at the selected control source until the
appropriate trigger event is detected.
STEP operation — When the trigger event is detected, a channel is measured. The scan
pointer then loops back to the control source and waits for the next trigger event to occur.
SCAN operation — When the trigger event is detected, all the channels in the scan list are
scanned. The scan pointer then returns to the control source and waits for the next trigger
event to be detected.

Keithley 2701 Specifications

General

Max Voltage	300 V
Max Current	3 A
Frequency Range	3 Hz to 500 kHz
Frequency Accuracy	0.01%
Weight	3.6 kg
Measurement Functions	Frequency, Temperature
Interface	IEEE-488 (GPIB), RS-232
DC Voltage Range	300 V
DC Current Range	3 A
AC Voltage Range	300V
AC Current Range	1 μA to 3 A
Resistance Accuracy	0.01%
Channels	10
Dimensions	213mm x 88mm x 370mm