User`s guide

Introduction to the 34980A 1
Agilent 34980A Mainframe User’s Guide 13
Scanning
The instrument allows you to combine a DMM (either internal or
external) with multiplexer channels to create a scan. During a scan, the
instrument connects the DMM to the configured multiplexer channels one
at a time and makes a measurement on each channel.
Before you can initiate a scan, you must set up a scan list to include all
desired multiplexer or digital channels. Channels which are not in the
scan list are skipped during the scan. By default, the instrument
automatically scans the list of channels in ascending order from slot 1
through slot 8 (channels are reordered as needed). If your application
requires non- ordered scanning of the channels in the present scan list,
you can configure a non- sequential scan. Measurements are taken only
during a scan and only on those channels which are included in the scan
list.
You can store up to 500,000 readings in memory during a scan and all
readings are automatically time stamped. The most recent readings are
always preserved in memory. You can read the contents of memory at
any time, even during a scan. Reading memory is not cleared when you
read it. Each time you start a new scan, the instrument clears all
readings stored in reading memory from the previous scan. Therefore, all
readings currently stored in memory are always from the most recent
scan.
You can configure the event or action that controls the onset of each
sweep through the scan list (a sweep is one pass through the scan list):
• You can set the instrument's internal timer to automatically scan at a
specific interval as shown below.
• You can also program a time delay between channels in the scan list
(see “Channel Delay” on page 120).
Scan List
t
t
Ch 1 Ch 2
Ch 3
Ch 4
Ch 5
Ch 6
t
1
t
2
t
3
t
4
t
5
t
6
Channel Delay
(0 to 60 seconds)