Mitsubishi Electric Mr.Slim PUHZ-SHW80VHA Service Manual page 33

<M-NET communication error>
Error Code Abnormal point and detection method
Address duplicate definition
This error is displayed when transmission
from the units of same address is detected.
A0
Note) The address and attribute displayed
(6600)
at remote controller indicate the
controller that detected abnormality.
Hard ware error of transmission processor
Transmission processor intended
to transmit "0", but "1" appeared on
transmission wire.
Note) The address and attribute display
A2
at remote controller indicate the
(6602)
controller that detected abnormality.
BUS BUSY
1. Overtime error by signal collision damage
Abnormal if transmitting signal is not
possible for 8-10 minutes continuously
because of collision of transmission.
2. Data could not reach transmission wire
for 8-10 minutes continuously because
of noise or etc.
Note) The address and attribute displayed
A3
at remote controller indicate the
(6603)
controller that detected abnormality.
Communication error with communication
processor
Defective communication between unit
processor and transmission processor
Note) The address and attribute display
A6 at remote controller indicate the
(6606) controller that detected abnormality.
OCH526
(Note) "Indoor unit" in the text indicates M-NET board in outdoor unit.
Case
1 There are 2 or more same
address of controller of outdoor
unit, indoor unit, FRESH
MASTER, or LOSSNAY.
2 Noise has entered into
transmission signal and signal
was transformed.
1 Error is detected if waveform is
transformed when wiring works
of transmission wire of outdoor
unit, indoor unit, FRESH
MASTER or LOSSNAY are
done, or polarity is changed with
the power on and transmission
data collides each other.
2 Defective transmitting receiving
circuit of transmission processor
3 Transmission data is changed
by the noise on transmission.
1 Transmission processor could
not transmit signal because
short cycle voltage of noise
and the like have entered into
transmission wire continuously.
2 Transmission quantity has
increased and transmission of
signal is not possible because
there was wiring mistake of
terminal block for transmission
wire (TB3) and terminal block
for central control (TB7) in
outdoor unit.
3 Transmission are mixed with
others and occupation rate
on transmission wire rose
because of defective repeater
(a function to connector or
disconnect transmission of
control and central control
system) of outdoor unit, then
abnormality is detected.
1 Data of transmission processor
or unit processor is not
transmitted normally because
of accidental trouble such as
noise or thunder surge.
2 Address forwarding from unit
processor is not transmitted
normally because of defective
transmission processor
hardware.
33
Judgment and action
Search the unit with same address as
abnormality occurred. If the same address is
found, turn off the power supply of outdoor
unit and indoor unit and FRESH MASTER or
LOSSNAY at the same time for 2 minutes or
more after the address is corrected, and turn
the power on again.
Check transmission waveform or noise on
transmission wire.
1 If the works of transmission wire is done
with the power on, turn off the power supply
of outdoor unit and indoor unit and FRESH
MASTER or LOSSNAY at the same time for
2 minutes or more, and turn the power on
again.
2 Check transmission waveform or noise on
transmission wire.
1 Check if transmission wire of indoor unit,
FRESH MASTER, LOSSNAY, or remote
controller is not connected to terminal block
for central control (TB7) of outdoor unit.
2 Check if transmission wire of indoor unit,
FRESH MASTER or LOSSNAY is not
connected to terminal block for transmission
wire of outdoor unit.
3 Check if terminal block for transmission wire
(TB3) and terminal block for central control
(TB7) is not connected.
4 Check transmission waveform or noise on
transmission wire.
Turn off the power supply of outdoor unit, indoor
unit and FRESH MASTER or LOSSNAY at the
same time for 2 minutes or more, and turn the
power on again. System returns normally if
abnormality was accidental malfunction. If the
same abnormality generates again, abnormality-
generated controller may be defective.