28 Service Manual SM-MDS_(ii)
3.4.4 Handsets Wiring
For Central Controller MC303, wiring work is needed between indoor units and the controller for communication
purpose. The communication wire used should comply with UL2547 or UL2791 standard (refer to Section 3.3,
page 18). Communication wire is wired from the controller to indoor units (through the orange connector, A
pc
and
B
pc
) through daisy chain connection. One end of the screen layer should be earthed to protect the signal
transmission. Kindly refer to the figure below for the illustration of the connection:
The length of the communication wire should not exceed 1000m. The Central Controller MC303 can be used
with both MC200-C and MC-201C indoor PCB. To ensure stable communication, jumper JP2 should be shorted
for the last indoor unit within the chain connection.