Device Actions; Output Trigger; Reading Hold (Autosettle) - Keithley 2000 User Manual

3-10 Measurement Options

Device actions

The primary device action is a measurement. However, the device action block could include
the following additional actions:
•
•
•

Output trigger

After the device action, an output trigger occurs and is available at the rear panel Trigger Link
connector. This trigger can be used to trigger another instrument to perform an operation (e.g.,
select the next channel for an external scan).
Counters
The trigger model for stepping and scanning contains additional blocks for counting samples
(the number of channels to scan) and counting triggers. These counters are explained in the para-
graph "Scan operations" later in this section.

Reading hold (autosettle)

When a hold reading is acquired as described in "Device actions", an audible beep is sounded
(if enabled) and the reading is considered a "true measurement". The reading is held on the dis-
play until an "out of window" reading occurs to restart the hold process.
When operating remotely or scanning, the hold process seeks a new "seed""once it has been
satisfied and the reading has been released. When operating from the front panel, the hold pro-
cess does not seek a new "seed" until the held condition is removed.
Filtering — If the repeating filter is enabled, the instrument samples the specified num-
ber of reading conversions to yeildl single filtered reading. Only one reading conversion
is performed if the filter is disabled, or after the specified number of reading conversions
for a moving average filter is reached. The output of filter feeds hold.
Hold — With hold enabled, the first processed reading becomes the "seed" reading and
operation loops back within the device action block. After the next reading is processed,
it is checked to see if it is within the selected window (0.01%, 0.1%, 1%, 10%) of the
"seed" reading. If the reading is within the window, operation again loops back within
the device action block. This looping continues until the specified number (2 to 100) con-
secutive readings are within the window. If one of the readings is not within the window,
the instrument acquires a new "seed" reading and the hold process continues.
Channel closure — When stepping or scanning, the last device action is to open the pre-
vious channel (if closed) and close the next channel. Using the hold feature provides an
auto settling time for the scanner relays. Each open/close transition will restart the hold
process and a reading for each channel will not occur until the relay settles.