GMV5 D.C INVERTER MULTI VRF SERVICE MANUAL
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Composition of the System Network
The network is composed of three parts:
Gree CAC Remote Monitoring System of the monitor network, including an RS232-485
Optoelectronic Isolated Converter.
Modbus gateways: They serve to bridge air conditioning unit network with the monitor network and
transmit data between the networks. Each Modbus gateway is configured with an address (realized
through an 8-bit DIP switch); value range: 1~255. Each gateway address within a system must be
unique.
Air conditioning unit network.
NOTICE!
A serial port for the monitor network can be connected to up to 255 Modbus gateways.
Modbus bus: L1 represents the Modbus bus which can support up to 255 Modbus gateways.
CAN2 bus: L2 represents the CAN2 bus which is the link to the Modbus gateway and the master
ODU.
CAN2 network: in one CAN2 network, a maximum of 16 air conditioning systems and 255 IDUs are
allowed. If exceeded, the CAN2 network should be divided into two.
Air conditioning system: one air conditioning system consists of at most four ODUs (among them
one is the master unit) as well as the matched IDUs.
Allowable number accessible to the gateway: one Modbus gateway can support at most 16 air
conditioing systems (each system includes at most 4 ODUs) and the total maximum allowable IDUs is
128. If exceeded, another Modbus gateway will be required as shown in CAN2 Network 2.
2.1.4 Hardware
2.1.4.1 List of Parts
Remote monitoring
part
ME30-24/E4(M)
Interconnect with remote monitoring
system:
Protocol interface: Modbus RTU
Hardware interface: RS485
Baud rate: 9600
Start bit: 1
Data bits: 8
Parity bit: none
Stop bit: 1
Main fittings: Modbus gateway,
instruction
Optoelectronic
isolated repeater
Optoelectronic
isolated repeater
RS485-W
For communication bus, set a
repeater every 800 m; for Modbus
gateways, add a repeater every 30
gateways.
Optoelectronic
isolated converter
Optoelectronic
isolated converter
GD02
This converter is required only when
remote monitoring systems work in
RS232 mode.