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Creating the scan list – Agilent Technologies L4400 User Manual

Page 83

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Operating and Programming

3

L4400 User’s Guide

71

While the scan is running, you can perform low- level control

operations on any channels on the digital modules that are not in the
scan. For example, you can output a DAC voltage or write to a digital
channel (even if the totalizer is part of the scan list). However, you
cannot change any parameters that affect the scan (channel
configuration, scan interval, Card Reset, etc.) while a scan is running.

If a scan includes a read of the totalizer, the count is reset each time

it is read during the scan only when the totalizer reset mode is
enabled.

At the end of the scan, the last channel that was scanned will be

opened (as well as any Analog Bus relays used during the scan). Any
channels that were opened during the scan will remain open at the
completion of the scan.

If you abort a scan that is running, the instrument will terminate any

reading in progress (readings are not cleared from memory). If a scan
is in progress when the command is received, the scan will not be
completed and you cannot resume the scan from where it left off. Note
that if you initiate a new scan, all readings are cleared from memory.

The Monitor mode is automatically enabled on all channels that are

part of the active scan list (see

“Monitor Mode"

on page 80).

The present scan list is stored in volatile memory and will be lost

when power is turned off or after a Factory Reset (

*RST

command).

Creating the Scan List

Usage:

L4421A 40- Channel Armature Multiplexer

L4450A 64- Bit Digital I/O (digital input, counter channels only)

L4452A Multifunction Module (digital input, totalizer channels only)

A scan list is created as follows:

Use the

ROUTe:SCAN

command to define the list of channels in the

scan list. To determine what channels are currently in the scan list,
use the

ROUTe:SCAN?

query command.

To add channels to the present scan list, use the

ROUTe:SCAN:ADD

command. To remove channels from the present scan list, use the

ROUTe:SCAN:REMove

command.

To remove all channels from the scan list, send “

ROUT:SCAN (

@

)

”.

To initiate a scan, use the

INITiate

or

READ?

command. Each time

you initiate a new scan, the instrument will clear the previous set of
readings from memory.

To stop a scan in progress, use the

ABORt

command.