Flex M Engineered Receiver Instruction Manual
May 2019
Page 49 of 50
Problems
Possible Reasons
Suggestions
Drive Connected
to Serial
Communication
Card does not
respond
LED #6 is lit up, module is
wired in test mode (drive
connection is being
simulated).
Ensure wiring of the drive(s) to the Serial
communication card is correct.
The MLC
(Master) Relay
turns off during
normal operation
The transmitter powered
TEST due to inactivity.
Extend the inactivity timeout setting for the
transmitter.
The transmitter powered
TEST due to low batteries.
Replace the transmitter's batteries.
The RF/Message LED stops
blinking for more than 3
seconds, followed by the
MLC Relay turning off.
Radio interference; change the system's
channel setting.
The RF/Message LED
stopped and the MLC Relay
turned off together within 1
sec, possibly when engaging
or disengaging another relay
that is driving a contactor.
CPU module is resetting. Install snubbers
across the coils of all contactors to reduce
transient voltages. Ensure that the power
module has a stable power source.
The MLC has turned off and
the watchdog LED is blinking
the amber LED 6 times.
Ensure that the transmitter is properly
communicating with the receiver and that
the START has been activated on the
transmitter.
The serial data timeout error
LED (LED #5) on the serial
communication card is lit.
Drive serial communication
is inactive or was inactive for
more than 1 sec. MLC Relay
turned off together when
LED is lit.
Error is reset when transmitter issues a start
command. Inspect serial communication
wiring to ensure there are no breaks, poor
connections, or damage to the wiring.
Digital Input
Module not
detecting an
input
Input voltage is greater than
36V and internal selector is
set to LOW band.
Verify input jumper is set to HIGH band for
voltages over 36V
Relay contacts
opposite from
what is expected
Contact state is selectable
for relays K1 and K2,
allowing active state to have
contacts either open or
closed.
Ensure jumpers for relays K1 and K2 are
installed in the desired positions.