ATI Technologies Scan Alarm C14, Руководство пользователя

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Input Filter
The Scanner has two different types of input filters:
•
A noise rejection filter that rejects high frequency input signal noise. This filter
keeps a “Trend Log” of input readings. If a reading is outside the filter’s
“acceptance band”, and later readings are within the acceptance band, the
Scanner ignores the anomalous reading. For Linear Inputs the acceptance
band is 0.5% above and 0.5% below the input reading trend. If later readings
are also outside the acceptance band, the Scanner accepts the anomalous
reading and calculates a new acceptance band, (You cannot adjust this input
filter).
•
A standard resistor-capacitor (RC) filter that lets you damp the input
response if inputs change unrealistically or change faster than the system
can respond. If the input filter is enabled, the process variable responds to a
step change by going to 2/3 of the actual within the number of scans you set.
If all input channels are enabled, none of them set to SKIP, the Scanner will scan
1.5 channels per second when set to 1 scan, and 4.5 channels per second when
set to 3 scans.
Selectable Values: 0 to 255 Scans.
Setup Channel Alarms
The Setup Channel Alarms menu lets you access menus which change alarm
function parameters for the current channel. The main menu alarms menu looks
like this:
The Scanner has two different kinds of alarms: global alarms, and process
alarms.
Global Alarms
Global alarms occur when a channel alarm is active and unacknowledged. (If an
alarm occurs, the Scanner front panel displays an appropriate alarm message,
see
Chapter 4: Using the Scanner). Even if the alarm condition goes away, the