Agilent 34980A Multifunction Switch/Measure Unit *34980-90005*
Agilent 34980A Multifunction Switch/Measure Unit *34980-90005*
Agilent 34980A Multifunction Switch/Measure Unit *34980-90005*
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3 Features and Functions<br />
Using Alarms With the Digital Modules<br />
You can configure the instrument to generate an alarm when a specific <br />
bit pattern or bit pattern change is detected on a digital input channel <br />
or when a specific count is reached on a totalizer channel (34950A and<br />
34952A). These channels do not have to be part of the scan list to<br />
generate an alarm. Alarms are evaluated continuously as soon as you<br />
enable them.<br />
The channel numbering scheme for the digital input and totalizer<br />
channels is shown below (s represents the slot number).<br />
Pattern comparisons always start on the lowest- numbered channel in<br />
the bank and extend to all channels involved in the channel width.<br />
Alarms are evaluated continuously on the digital modules, but alarm<br />
data is stored in reading memory only during a scan.<br />
Each time you start a new scan, the instrument clears all readings<br />
(including alarm data) stored in reading memory from the previous<br />
scan. However, alarm data stored in the alarm queue from the digital<br />
modules is not cleared. Therefore, although the contents of reading<br />
memory are always from the most recent scan, the alarm queue may<br />
contain data that occurred during previous scans or while the<br />
instrument was not scanning.<br />
Front Panel Operation:<br />
Digital Input Channel<br />
Numbering<br />
34950A s101 through s104<br />
s201 through s204<br />
34952A s001 through s004 s005<br />
Totalizer Channel Numbering<br />
s301, s302<br />
To configure an alarm on a digital input channel, choose from the<br />
following items and then set the desired patterns for the compare data<br />
and mask. Set each bit to “0” or “1”. <br />
<br />
Alarm > COMPARE DATA > COMPARE MASK<br />
You can either specify that an alarm will occur when certain bits<br />
change or when a specific pattern is read:<br />
<br />
Alarm > COMPARE FOR > EQUAL|NOT-EQ<br />
To configure an alarm on a specific totalizer count, select:<br />
<br />
Alarm > TOTALIZER LIMIT<br />
138 <strong>Agilent</strong> <strong>34980A</strong> Mainframe User’s Guide