The Armstrong Monitoring Corporation AMC-400 Series, User Manual

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AMC-400 Series Digital Transmitter with Smart Sensor 2
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Below is the possible Transmitter Status LED:
Transmitter LED State
Definition Action
Slow Blinking Red Transmitter initializing. Wait for initialization to complete.
Slow Blinking Green Transmitter is healthy. No action required.
Fast Blinking Green Transmitter is healthy, but
no MODBUS
communication detected. Check if monitor is MODBUS
connected and not in setup.
Slow Blinking Green/Red Transmitter is in
configuration mode.
Complete configuration and exit.
Fast Blinking Green/Red Transmitter is in gassing
state of calibration. Complete calibration and exit.
Fast Blinking Red Transmitter has
experienced a minor fault
in the last 10 seconds of
operation. Check if transmitter and/or other
system components have valid
operating limits (i.e. connections,
power supply, temperature, and
MODBUS addressing). Consult AMC
for service if status persists.
Solid or long period Red,
Green or Orange Transmitter has
experienced a severe
fault. Wait one to two minutes for unit to
enter normal mode. Consult AMC for
service if status persists.
LED Extinguished Transmitter is powered
off. Check transmitter wiring or power
supply state. Consult AMC for service
if status persists.
5.1.4 TROUBLESHOOTING MODBUS USING THE TRANSMITTER STATUS LED
The Transmitter Status LED indirectly provides a MODBUS monitor function. Using this LED in
conjunction with other transmitters can help in diagnostic of MODBUS faults. Here is a list of
troubleshooting guidelines of the Transmitter Status LED:
A. If all transmitters blink fast green and the monitor is in operation mode then the
MODBUS wiring is likely disconnected at the monitor.
B. If one or more transmitter(s) in a chain are blinking fast green and a unit closer to the
monitor is blinking slow green then a MODBUS disconnection point begins after the
slow blinking green unit.
C. If a transmitter is blinking fast red and other transmitter units are blinking slow green
then check that the MODBUS connections are not reversed on the flashing red unit.
D. If a transmitter blinks slow green, but the monitor indicates “na” for that unit then the
transmitter unit needs its MODBUS address to be assigned.
E. If two transmitter units blink slow green, but all other transmitter units indicate fast
blinking red, then the two slow blinking green transmitter units have the same MODBUS
address.
F. If the monitor appears to be operating well with one or more transmitters, but transmitter
unit(s) have fast blinking red from time to time, then MODBUS signal degradation is
present. Check that the both MODBUS signals wires and shield are properly connected.