Sinclair SDV 6 Service Manual page 83

1) The UP communication port of 1# repeater is connected to the communication port of 10# IDU, and the
DOWN communication port of 1# repeater is connected to the communication port of 11# IDU.
2) The UP communication port of 2# repeater is connected to the communication port of 20# IDU, and the
DOWN communication port of 2# repeater is connected to the communication port of 21# IDU.
3) For each repeater added, 10 IDUs and 200 m communication distance can be added. A refrigerant
system allows the addition of a maximum of 2 repeaters and can connect to up to 30 IDUs. If more than 30
IDUs are connected, please allocate separate refrigerant systems.
3. If communication cables connecting the communication ports of the repeater, IDU and ODU form a
closed loop, it will cause a communication fault.
4. RS-485 communication cables must be connected hand in hand. If communication is unstable, a
matching resistor needs to be added to the last IDU on the PQ (in the accessory bag of the ODU). However,
a matching resistor should not be added between M1 and M2. Otherwise, a communication fault may occur.
5. To select the communication mode Link (M1M2), users must go to the ODU menu item to change the
mode (For the setting method, refer to the ODU Installation Manual). Otherwise, communication faults
may occur.
6. The SDV6 plat. ODU typically uses the SDV6 communication protocol. If there are any IDUs that use
a non-SDV6 plat., users must go to the ODU menu item to change the communication protocol (Please
refer to the ODU Installation Manual for setup instructions). Otherwise, these IDUs will display
communication fault codes (For the code number, please refer to the IDU wiring nameplate).
80
Figure 1 Schematic diagram of Link communication cable connection
Upstream IDU and ODU of repeater 1# (including master ODU)
IDU 10#
Repeater 1#
IDU 11# IDU 20#
Downstream IDUs
of repeater 1#
Upstream IDUs
of repeater 2#
Master ODU
IDU 1#
Repeater 2#
IDU 21#
Downstream IDUs of repeater 2#
IDU 30#