Section 9 – Servicing (Continued)
101
DSMR2
Red
Monitors closure of the Master Control Relay (MCR) relay (K13).
LED will be illuminated when the MCR relay has been enabled by an ON command recieved
from the Transmitter Unit. LED will extinguish when an OFF command has been transmitted, an
EMS condition is present, or SW2 is set to OFF.
The MCR controls the 12 VDC power to the Master Relay on the Power Supply Board.
DS1-DS12 Red Monitors closure of the output relays (K1-K12).
Normally ON
for a function when that specific function is enabled.
The LED will be illuminated when a specific relay has been enabled by the respective command
received from the Transmitter Unit. The LED will extinguish when the command is no longer
detected.
DS13
Red
Monitors the watchdog timer.
Normally OFF.
The LED will illuminate momentarily when power is applied to or removed from the system. If
the LED is continuously flashing or on, the computer is not working properly. If LED is
illuminated constantly (no flashing), the +5 VDC is probably too low. This could be caused by
shorts on the board or by a defective voltage regulator. If the LED flashes at a constant rate, the
microcomputer chip or EPROM may be defective.
DS14
Yellow
Monitors data synchronization (flashes when a properly formatted data signal is received from the
transmitter).
This LED will flash rapidly when data is transmitted. The LED can be used with DS16 to analyze
incoming data. If DS16 is illuminated or flashing when DS14 also is flashing, another Transmitter
Unit on the same frequency may be present. This is normal. As more Transmitter Units operated
on the same frequency, the LED will flash brighter and more often.
DS15
Yellow
Monitors continuity between receiver RF module and CPU module.
Normally ON.
Off indicates a malfunctioning receiver.
DS16
Check
this
first!
Red
Monitors received data errors.
Wrong Access Code.
Normally OFF.
If LED is illuminated continuously when data is transmitted and the system will not respond, the
Access Code of the Receiver and Transmitter Units may not match. A flashing LED during data
transmission may indicate interference of the received data. If LED is illuminated when data is not
transmitted, another Transmitter Unit may be present on the same frequency with a different
Access Code. The presence of activity on this LED does not necessarily indicate a problem. It
should be used with other indicators in analyzing system status.
DS17
Yellow
Monitors system acitivty.
Normally FLASHING.
If not flashing the microprocessor is dead.
