Rules for cascading devices via RS485

On this article you will find out basic information about cascading Huawei inverters.

Cascading with SmartLogger 3000 by RS485 -> Modbus RTU

Maximal inverters per SmartLogger

Smartlogger3000 A (01 ; 03) = 80 inverters COM1(30) COM2 (30) COM3 (20)

Smartlogger3000 B = 150 inverters  COM1(50) COM2 (50) COM3 (50)

If the SmartLogger supporting communication via RS485 and ACmbus it is also possible to cascade devices like this way.

In this scenario (picture bellow) is the master device SM3000 and the devices like Smart Power Meter, EMI (Meteo Station) you have to use communication / connection by RS485. 

Note: ACMbus communication is only for Huawei devices, not supported for 3rd party devices (power meter, EMI and others).

Other devices like inverters are connected in series on RS485 communication. No need to use end resistance at the last device

On SL3000 you can find out 3pcs of COM ports which are designed for this kind of comunication

On each inverter you will find communication connector. For cascading you are using 1 & 3 PINS ( IN - input) and 2 & 4 PINS (OUT - Output).

The right scenario for connection is from COM (1-3) port: 1st Inverter (from Logger 1 & 2 - input ; 2 & 4 - Output) on 2nd inverter (from previous inverter 1 & 2 - input ; 2 & 4 - Output) and like this way

Maximal distance between devices is 100m, max distance per RS 485 line is 1000m.

Note: when you have SL3000 you did not connect or use Smart Dongle  => you are using only one master device.

Cacading with Smart Dongle, RS485 -> Modbus RTU:

In this case you will choose one inverter as a Master Device and where you connect SmartDongle there you are connecting the Power Meter or other devices.

Inverter with SmartDongle is the Master Device... others in cascade are SLAVE devices.

Connection in this scenario is: 1st Master Inverter (; 2 & 4 - Output) on 2nd Slave inverter (from previous inverter 1 & 2 - input ; 2 & 4 - Output) and like this way

On last Slave inverter you are not using end resistance.

Cascading with SmartDongle is limited to max 10 devices (one device as master and nine devices as SLAVE). Maximal distance between devices is 100m and maximal lenght per RS485 line is 1000m.

Note: in this scenario - Cascading with SmartDongle you are using only one Smart Dongle in cascade => not possible to use 2pc of SmartDongle

Additional note: On cascading M1 inverters with batteries, you can cascade maximal 3 inverters.