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Model 2018 Operations Manual Rev Apr 2020 Page
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OFF when below 50V
RMS
. Red Enable and Special Function Inputs are ON when their voltage is
above 70V
RMS
and OFF when below 50V
RMS
.
With the LED thresholds, the monitor—when checking for Conflicts, Multiple Indications, and Short
Yellows— senses greens, yellows, and reds as ON when their voltage is above 25V
RMS
and OFF when
below 15V
RMS
. The Red Fail checks greens, yellows, and reds as ON when their voltage is above
70V
RMS
and OFF when below 50V
RMS
. Red Enable and Special Function Inputs are ON when their
voltage is above 70V
RMS
and OFF when below 50V
RMS
.
The signal monitor portion of the monitor checks for the presence of voltage on conflicting field connection
terminals in the Controller Assembly. For the purpose of conflict determination, a signal on any of the Green or
Yellow inputs associated with a channel shall be considered as that channel being active.
The signal monitor portion of the monitor also checks for the absence of any required signal voltage on each
channel at the field connection terminals in the Controller Assembly. For this purpose a signal on the Green,
Yellow, or Red inputs associated with a channel shall be considered as that channel being active.
The voltage monitor portion of the monitor is capable of monitoring the Controller Watchdog output that indicates
satisfactory operating conditions in the Controller Unit and the +24 volt direct current power supply.
The Model 2018 is fully programmable. An interchangeable Program Card is provided to allow the assignment of
permissive or compatible channels. Programming is accomplished through the use of diodes soldered on the
Program Card. The Program Card may be a sixteen- or eighteen-channel card. The Program Card is inserted into
the monitor through a slot in the front panel. Two jumpers on the main board are available to force the monitor to
accept only one of the two types of program cards.
