Gree GMV-224WM/B-X, Service Manual

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GMV5 DC INVERTER VRF UNITS SERVICE MANUAL
273
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.
Note
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.
1.4 Hardware
1.4.1 List of Parts
Name Type BOM Supply
Range Remark
Modbus
gateway suite
Remote
monitoring part
ME30-24/E4(M)
MC20000060
SC
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
EN02200010
Optional
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
EN02200020
Optional
This converter is required only
when remote monitoring
systems work in RS232 mode.
Control cabinet /
/ Prepared
by users
1.4.2 Modbus Gateway
1.4.2.1 Functions
GREE Modbus gateways for the central air conditioning system are used to bridge the internal network
of the air conditioning system (CANbus) and the monitoring network (Modbus). It will provide the Gree
web-based remote monitoring and control system/BMS communication interfaces and is enabled to take
the real-time monitoring and the long-distance control to the air conditioning system. Also, it will provide
the Modbus RTU protocol, five digital inputs and five digital outputs, among which the DI1 is defined for
the fire alarm input (when the fire alarm signal is input, the Modbus gateway will stop the air conditioning
system immediately).