Mitsubishi Electric PURY-P200 Service Handbook page 164

2. MA remote control transmission
The MA remote control and indoor unit communicate with the current tone burst method.
(1) Symptoms caused by infiltration of noise on transmission cable
If noise, etc., infiltrates the transmission cable and the communication between the MA remote control and indoor
unit is cut off for three consecutive minutes, a MA communication error (6831) will occur.
(2) Confirmation of transmission specifications and waveform
MA remote controller
Transmission waveform (Across terminal No. 1-2)
Logical 1
TB15
Indoor unit
Logical 0 Logical 1 Logical 1
- 161 -
A1, B2: No polarity
1
Across terminal No. 1-2 :
2
Power supply (8.5V to 12VDC)
(1) 2msec/bit ± 5% must be satisfied
(2) Voltage across terminal No.1-2 must
be within range shown on left.