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Features and Functions
148
Keysight 34980A Mainframe User’s Guide
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.
Any channel that can be “read” by the instrument can also be included in a scan.
This includes any combination of temperature, voltage, resistance, current,
frequency, or period measurements on multiplexer channels. A scan can also
include a read of a digital channel or a read of the totalizer count on the digital
modules. Scanning is allowed with the following modules:
– 34921A through 34925A Multiplexer Modules
– 34950A Digital I/O Module (digital input and counter channels only)
– 34952A Multifunction Module (digital input and totalizer channels only)
Automated scanning is not allowed with the other switching modules. In addition,
a scan cannot include a write to a digital channel or a voltage output from a DAC
channel. You can, however, write your own program to manually create a “scan” to
include these operations.
Rules for Scanning
– 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 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, see
Measurements are taken only during a scan and only on those channels which
are included in the scan list.
– You can store at least 500,000 readings in memory and all readings are
automatically time stamped. If memory overflows, a status register bit is set
and new readings will overwrite the first (oldest) readings stored. The most
recent readings are always preserved. You can read the contents of memory at
any time, even during a scan. Reading memory is not cleared when you read it.
