Mitsubishi Electric AE-200A Service Handbook page 58

[V Troubleshooting]
Error Description and method
code of detection
Communication error -
Transmission processor
hardware error
The transmission
processor intended to
send "0" but "1" is
output on the
transmission line.
6602
Communication error -
Transmission line busy
1. Collision over error.
Error when the state
of data not being able
to be transmitted
continues for a period
of 4 to 10 minutes due
to a transmission
6603
collision.
2. Error when the state
of data not being
output to the
transmission line
continues for a period
of 4 to 10 minutes due
to, for example, noise.
Cause
Cause 1) When work was performed or the polarity was changed for the transmission line of either
an indoor unit or outdoor unit while the power was left on, the waveform changed and an
error was detected when the transmission data collided.
Cause 2) When a 100 V power supply was connected to the indoor unit.
Cause 3) Ground fault of the transmission line.
Cause 4) When a power supply unit for the transmission line is not used in a system with the
AE-200/AE-50/EW-50 connected, the power jumper is inserted in CN40 on multiple
outdoor units.
Cause 5) When a power supply unit for the transmission line is used in a system with the
AE-200/AE-50/EW-50 connected, the power jumper is inserted in CN40 on one of the
outdoor units.
Cause 6) Failure of the controller on which the error occurred.
Cause 7) When the transmitted data changed due to noise during transmission.
Cause 8) Defective AHC ADAPTER
Refer to the CITY MULTI (Outdoor Unit) Service Handbook.
1) The transmission processor is in the
state of being unable to transmit due to
a voltage of a short period such as
noise continuing to be generated and
causing an interference on the
transmission line.
2) Failure of controller on which error
occurred.
3) Defective AHC ADAPTER
54
Check procedure and remedy
Check the transmission waveform and noise on
the transmission line. Perform the check in
accordance with <Transmission waveform and
noise check procedure>.
→ If there is no noise, the controller at the
source of occurrence has failed.
If the AE-200/AE-50/EW-50 has failed,
replace the AE-200/AE-50/EW-50.
→ If there is noise, refer to "V [4] M-NET
transmission waveform and noise check
procedure."
Refer to the CITY MULTI (Outdoor Unit) Service
Handbook.