Gree GMV5 Series Service Manual page 284

0
1
1 2 3
(3) Function DIP Switch-CAN Bus Matched Resistance Setting
Precaution
The master ODU of air conditioning system or the gateway located at either end of the CAN2 bus (see
the topological drawing) should include a matched resistance; otherwise the normal communication
would fail.
The eighth position of this function DIP switch is used to set the matched resistance of the CAN2 bus.
When the Modbus gateway is located at either end of the CAN2 bus, it shall be coupled with a matched
resistance and the eighth position should be set to ―0‖.
When the Modbus gateway is located at neither end of the CAN2 bus, no matched resistance is required
the eighth position should be set to ―1‖.
ODU system 1 ODU system 2
Master outdoor unit 1 Master outdoor unit 1
Master ODU of Master ODU of
ODU system 1 ODU system 2
Master outdoor unit 1 Master outdoor unit 1
ODU system 1 ODU system 2
With the matched Without the
resistance matched resistance
With the matched Without the
resistance matched resistance
The following figure shows how to set matched resistance:
0
1
1 2 3 4
Function
Note: The master ODU at either end of the CAN2 bus must be configured with matched resistance as
well. The following figure shows how to set matched resistance for GMV5 DC converter multi-online air
conditioning units and specific position:
(4) Function DIP Switch-RS485 Bus Matched Resistance Setting
The seventh position of this function DIP switch is used to set the matched resistance for the RS485 bus
(herein, it is the Modbus bus)
GMV5 DC INVERTER VRF UNITS SERVICE MANUAL
4 5 6 7 8
Address DIP
CAN2 bus
CAN2 bus
......
......
5 6 7 8
Master outdoor unit
Matched resistance
Address Code
Address DIP
1 2 3
1 1 0 1 0 1 0 0 43
ODU system 16
Master outdoor unit 1
Master ODU of
ODU system 16
Master outdoor unit 1
ODU system n
Without the
matched resistance
Without the
matched resistance
Without
matched
resistance
configured
8 8
indicates the position
of toggle switch
Matched
resistance
Master ODU
281
Add
4 5 6 7 8
With the matched
resistance
With the matched
resistance
With
0
matched
resistance
configured
1