Scan Operation; Basic Scan - Keithley 2750 User Manual

Model 2750 Multimeter/Switch System User's Manual

Scan operation

A basic scan is controlled solely by the STEP and SCAN keys. When one of these keys is
pressed, the STEP or SCAN operation will be performed. For the manual/external trigger
scan, the TRIG key or triggers received from another instrument starts the STEP or SCAN
operation. For the monitor scan, a channel monitors readings. When a set reading limit is
reached, STEP or SCAN will start.

Basic scan

Perform the following steps to run the presently configured scan:
1.
2.
3.
4.
5.
NOTE
6.
Buffer
To recall scanned readings stored in the buffer, press RECALL and use the
∇
keys to navigate through the buffer. Note that the buffer can be read while the instru-
ment is storing readings. See
ished, make sure to exit from buffer recall by pressing the EXIT key.
resumed. Error +517 occurs (cannot resume scan) to indicate that the scan has
been disabled. The instrument assumes the normal power-on setup.
The Model 7706 does not support auto scan. Trying to enable auto scan with a
Model 7706 card installed will cause error -221 (settings conflict).
To start the scan, press STEP or SCAN.
The STEP or SCAN annunciator turns on, and channels are scanned from the low-
est to highest number channel. Channels that are turned off will not be scanned.
Keep in mind that the Timer Delay for STEP occurs between channels, while the
Timer Delay for SCAN occurs between scans. If the timer is off, both scans will
run at virtually the same speed.
With reading count set to a finite value, the last channel scanned will open and the
first channel in the scan list will close. Keep in mind that the scan is still enabled
(STEP or SCAN annunciator on). When you press STEP or SCAN, the scan will
continue starting with the next channel.
With reading count set to infinite, the scan will keep repeating.
While the scan is enabled (STEP or SCAN annunciator on), most front panel keys
are inoperative and will cause the message "HALT SCANNER" to be displayed.
To disable the scan, press SHIFT and then HALT.
Section 6 for details on recalling buffer readings. When fin-
Scanning 7-21
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