Mitsubishi Electric Mr. Slim PUZ-M200YKA2.UK Service Manual page 38

<M-NET communication error>
Check Code Abnormal points and detection method
Address duplicate definition
This error is displayed when transmission
from the units of same address is detected.
Note: The address and attribute displayed
A0
at remote controller indicate the
(6600)
controller that detected abnormality.
Hardware error of transmission processor
Transmission processor intended to transmit
"0", but "1" appeared on transmission wire.
Note: The address and attribute display at
remote controller indicate the controller
that detected abnormality.
A2
(6602)
BUS BUSY
Overtime error by collision damage
Abnormal if transmitting is not possible for
8 to 10 minutes continuously because of
collision of transmission.
Data could not reach transmission wire for
8 to 10 minutes continuously because of
noise, etc.
A3
(6603) Note: The address and attribute displayed
at remote controller indicate the
controller that detected abnormality.
Communication error with communication
processor
Defective communication between unit
processor and transmission processor
Note: The address and attribute display at
remote controller indicate the controller
A6
that detected abnormality.
(6606)
OCH775B
Note: "Indoor unit" in the text indicates M-NET board in outdoor unit.
Cause
There are 2 or more same
address of controller of outdoor
unit, indoor unit, FRESH
MASTER, or LOSSNAY.
Noise has entered into
transmission signal and signal
was transformed.
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 collide each
other.
Defective transmitting receiving
circuit of transmission processor
Transmission data is changed by
the noise on transmission
Transmission processor could
not transmit signal because short
cycle voltage of noise and the like
have entered into transmission
wire continuously.
Transmission quantity has
increased and transmission 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.
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.
Data of transmission processor or
unit processor is not transmitted
normally because of accidental
trouble such as noise or thunder
surge.
Address forwarding from unit
processor is not transmitted
normally because of defective
transmission processor hardware.
38
Judgment and action
Search the unit with same address as
abnormality occurred. If the same address
is found, shut 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.
If the works of transmission wire is done
with the power on, shut 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.
Check transmission waveform or noise on
transmission wire.
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.
Check if transmission wire of indoor
unit, FRESH MASTER or LOSSNAY
is not connected to terminal block for
transmission wire of outdoor unit.
Check if terminal block for transmission
wire (TB3) and terminal block for central
control (TB7) is not connected.
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 occurs
again, abnormality-occurred controller may be
defective.