Auto Clock Sync; Clock; Performing Checkback Tests; Manual Request From Web - Ametek UPLC CU44-VER04 Applications Manual

nuisance alarms. With this window and the
delayed alarm, you can design a system that only
alerts you when a true, long-term problem exists.
The valid range for this window is 1 to 24 hours.

7.4.15 Auto Clock Sync

When the auto clock sync is enabled, the master
synchronizes all remote clocks to its own time,
starting at 12:30 a.m. In practice, the synchroniza-
tion is rough, within about +/- 2 seconds. But that
is sufficiently accurate for Timed checkback test-
ing.

7.4.16 Clock

You set the clock's date & time via the front panel,
using the 24-hour format, specifying all four dig-
its for the year.

7.5 Performing Checkback Tests

The Automatic Checkback system's primary func-
tion is to perform checkback tests, verifying that
your carrier communication path is operating. You
can perform checkback tests in several ways:
• Manual request from the front panel tests
• Manual request from the web pages

• Automatic timed test

• Automatic periodic test

• Automatic carrier recovery

• Remote-initiated tests (via an input)
7.5.1 Manual Request from Web Pages
By clicking on the left-hand navigator
"Checkback", you can run manual tests, clear
events, counts and alarms. Sample test results are
shown in Figure 7–2.
7.5.2 Automatic Timed Test
When this option is enabled, the master checkback
initiates checkback tests at four user-specified
times. For example, you might set these times to
be 4:00, 13:00, 14:00, and 23:00. You can only set
times to the nearest hour. The test then occurs at
the start of the hour plus five minutes, unless the
unit is busy with another message.
May 2012
Chapter 7. Optional Testing Facilities
7.5.3 Automatic Periodic Test
Instead of a timed test, you can set the master
checkback to initiate tests periodically, say, every
four hours. The shortest interval you can set is one
hour, and the longest is 120 hours. The periodic
interval is reset after one of the following:
• Sending or receiving a good checkback
test, including manual tests
• Attempting to execute a checkback test at
the Periodic Interval
7.5.4 Automatic Carrier Recovery
You can set a unit to begin more frequent tests
after failing any of the above checkback tests.
With the carrier auto recovery mode enabled, the
master, after failing a test, switches to carrier
recovery mode. In carrier recovery mode, check-
back tests are performed periodically, but much
more frequently than otherwise, for example,
every 20 minutes. You can set this time from five
minutes to one hour. After three consecutive suc-
cessful tests, the carrier recovery output is set, and
the master reverts to the normal automatic tests.
You can accelerate recovery by performing manu-
al tests at the master unit. After you execute three
successful manual checkback tests, the master
counts these as carrier recovery tests and reverts to
normal mode. Note that while in recovery mode,
the master only sends low-power checkback tests.
This ensures that the line conditions are good
before resuming normal operation.
After passing the three tests, any user defined out-
puts set to carrier recovery are set for five seconds.
7.5.5 Remote-Initiated Periodic Tests
In some cases, a remote initiates its own check-
back test. You can always manually request a test
via the Web pages or Front Panel test menu. But
the remote automatically does a checkback test if
it detects the master is late. When a remote is set
to do automatic periodic tests, it determines the
master is late if it does not receive a checkback
request within the user period plus some delay, or
grace period. For remote #1, this grace period is
five minutes.
7
Page 7–7