Chapter 3 - Device Overview
60 3BHS335648 E82 UNITROL 1020 User Manual
DCH Supervision Functions
The DCH Supervision has a total of 23 status signals from different supervision functions.
It also has two Monitor Alarm outputs that can be configured to generate a (global) Alarm
and/or a (global) Trip. As shown in Figure 3-11, Alarm and Trip status signals are
configured by a so called Configuration Matrix. Alarm and Trip are independent of each
other and they can be configured differently.
The Configuration Matrix allows the user to select which monitoring function will produce
an Alarm and/or a Trip at the output of the Supervision function. For instance, as soon as
a monitoring function, which is configured to produce an Alarm, reports a failure, the
Alarm status at the output of the Configuration Matrix will be set to active (logical true).
The same could happen to the Trip status if the monitoring function is configured to
produce a Trip. The configuration of Alarm and Trip is handled independently of each
other and therefore it provides great flexibility when engineering a project-specific
system.
Each monitoring function that can be configured in the Configuration Matrix has a status
which is used to detect the failure and triggers Alarm and/or Trip according to the
configuration. The status from each monitoring function is implemented with a latch
memory which makes the value remain active (logical true) even after the failure has
been diminished and the monitoring function no longer reports a failure. Therefore, it is
possible to determine which monitoring function causes an Alarm or Trip even after de-
exciting the machine. The latch memory of all monitoring function statuses can be
cleared by the digital input "Reset Alarm" (only if the failure has already been diminished)
or by powering off the device (Figure 3-11).
Alarm assignation
.
.
.
Trip assignation
1
2
21
20
3
.
.
.
Status
(Latch)
Monitor
Functions
(8)
DCH Supervision
Suppervission
Functions
(19)
Alarm status
Standby
config
Standby
config
to DO
port
Trip status
Configuration Matrix
Suppervission
Each status signal is
latched
when it goes to On or Logic 1
( edge detection )
Reset
Reset clears (to Logic 0) each
latched status only when the one
from the monitoring function is
already Off or Logic 0.
Trip and Alarm status
may be monitored from
the user interfaces
Alarm and Trip may be
configured to output or
not its status during the
Channel is in Standby
Alarm status
Standby
config
Alarm assignation
Figure 3-11 Double Channel Supervision.
To Next Page
Loading...
