User manual

Device actions
The primary device action is a measurement. However, the device action block could in-
clude the following additional actions:
• Filtering — If the repeating filter is enabled, the instrument samples the specified
number of reading conversions to yeildl single filtered reading. Only one reading con-
version 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 pro-
cessed, 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) consecutive 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 pro
-
cess continues.
• Channel closure — When stepping or scanning, the last device action is to open the
previous channel (if closed) and close the next channel. Using the hold feature pro-
vides an auto settling time for the scanner relays. Each open/close transition will re-
start the hold process and a reading for each channel will not occur until the relay
settles.
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 opera-
tion (e.g., select the next channel for an external scan).
Counters
The trigger model for stepping and scanning contains additional blocks for counting sam-
ples (the number of channels to scan) and counting triggers. These counters are explained
in the paragraph “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 display 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 process does not seek a new "seed" until the held condition is removed.
2000-900 (J - Aug 2010) BOOK.fm Page 10 Wednesday, October 12, 2011 12:29 PM