1. General Protocol

1.1 Overview of the Protocol

This document specifies the protocol for communication between the company’s hybrid inverter and a PC. It is a subset of the MODBUS protocol. For the standard MODBUS RTU protocol format please refer to www.modicon.com.

1.2 Communication Interface

The serial communication port uses standard RS485. The transmission is asynchronous with: 1 start bit, 8 data bits, 1 stop bit, and no parity bit. The default baud rate is 9600bps (options include 2400, 4800, or 9600). Data is transferred in "big-Endian" order (e.g. 0x12345678 is sent as 0x12, then 0x34, then 0x56, and finally 0x78).

1.3 Communication Method

The communication is based on a master-slave simplex model. Up to 32 slaves can be connected on the RS485 bus. The master polls each slave; if a slave does not respond or returns an error message, the communication is considered to have failed.

2. Protocol Frame

2.1 Protocol Frame Format

The structure of the Modbus frame is as follows:

• Byte 0: Slave address (ID)
• Byte 1: Function code
• Bytes 2 to N+1: Data
• Byte N+2: Check code (CRC)

2.2 Protocol Frame Description

ID: The slave (module power) address where 0 is the broadcast address, and all slave addresses must be unique on the bus.
Function Codes (FUNC):

• 0x03: Read holding registers to query inverter information
• 0x04: Read input registers to query inverter information
• 0x06: Write a single register and execute a remote instruction
• 0x10: Write multiple registers to set inverter information

CRC Calculation

The CRC is a 16-bit code calculated over the data bytes (start and stop bits not included). The method is as follows:

1. Initialize a 16-bit register to 0xFFFF.
2. For each byte in the message, perform a bitwise OR with the lower 8 bits of the register.
3. Shift the register right one bit and fill the highest bit with 0. Check the bit shifted out.
4. If the shifted out bit is 1, XOR the register with the polynomial 0xA001.
5. Repeat the shift (and XOR, if required) 8 times for each data byte.
6. After processing all bytes, exchange the high and low bytes of the CRC register.

3. Inverter Information Address Table

3.1 Inverter Basic Information (04H Read)

This section details registers that include parameters such as the PV input voltage, current, power, and energy values. For example:

• 3000: PV1 Input Volt (2 bytes, 0.1V resolution, unsigned 16-bit)
• 3001: PV2 Input Volt (2 bytes, 0.1V resolution)
• Registers 3012, 3013: PV currents (0.01A resolution, signed 16-bit)
• Registers 3024, 3025: PV input power (1W resolution)
• Energy registers (Day, Month, Year, and Total Energy with various resolutions)

3.2 Inverter System Information (03H)

System information such as inverter model, battery name, ARM/DSP versions, and other system-specific parameters are read using function 03H.

3.3 Inverter Setting (10H)

The inverter settings include configuration of time settings, inverter serial number, and other programmable parameters. Data is typically set by writing multiple registers concurrently.

3.4 Executing Commands (06H)

Remote commands (e.g., Reboot inverter, Remote shutdown) are executed using the 06H function code.

4. Protocol Implementation Examples (For Reference Only)

4.1 Querying Basic Information

Example (Master Request):
01 04 0B B8 00 01 B3 CB
Format: ID, FUNC, Address, Length, followed by CRC.
Example (Slave Response):
01 04 02 00 65 79 1B

4.2 Querying System Information

Example (Master Request):
01 03 0C 80 00 01 86 B2
Example (Slave Response):
01 03 02 4B 53 CE 89

4.3 Setting the Inverter Clock

For example, to set the clock to Tuesday, November 2, 2010, 14:30:00 the master would send a write command with the following bytes after the header:

Master Bytes (Partial):
01 10 0C A7 00 07 0E 31 ...
(Data bytes encode the date and time in ASCII.)

4.4 Setting the Weak_Peak Time

Example values:
Charging start: 11:24
Charging deadline: 11:25
Discharge start: 11:26
Discharge deadline: 11:27

4.5 Executing Remote Commands

Example: To limit maximum power to 85%, the master might send the following command:
01 06 0F B3 00 55 BB 06
The slave echoes the command if successful.

Revision History

• V1.0 – Added KSE hybrid inverter (2020.04.17)
• V1.1 – Modified the overfrequency, overvoltage, and undervoltage ranges (2020.12.31)
• V1.2 – Added querying function codes (2021.01.15)
• V1.3 – Added Brazil, South Africa, 50549 and other standards (2021.02.03)
• V1.4 – Charge and discharge quantity for newly added batteries (2021.04.06)
• V1.5 – Modified PV, buy power, sell power, load power unit from 1 kWh to 0.1 kWh; added national standard Ireland (2021.04.28)
• V1.6 – Added maximum battery pack temperature and cumulative protection time (2021.05.26)
• V1.7 – Added PV power from grid-connected, charging source distinctions, and load source indicators (2021.10.12)
• V1.8 – Added five battery packs (addresses 3441 to 3660) (2021.11.04)
• V1.9 – Added advanced peak load filling function, off-grid battery discharge depth, generator mode, battery pack forced wake up, manual heating film control, CT direction (2021.11.16)
• V2.0 – Added grid standard subdivision, AC coupling enable, BMS discharge depth enable; grid standard added Israel, Poland, Chile (2022.02.16)
• V2.1 – Added Charge from grid MAX SOC, GFCI Check Enable, VRT Enable, Warning flags for BMS updating and version errors (2022.02.23)
• V2.2 – Added parameters corresponding to phase S and T (2022.04.02)
• V2.3 – Supplemental English translation of battery pack parameters (2022.07.29)
• V2.4 to V2.5 – Added three-phase model registers (PV temperature, LLC temperature, battery pack details, DSP2 version, etc.) (2022.08.17/18, 2022.11.17)
• V2.6 – Added grid standards for Sweden, Denmark, Austria; added registers like parallel enable, PV startup voltage; CSA models, trip times, and QU/QP curve settings (2023.07.05, 2023.12)
• V2.7 – Added zero ground voltage detection, demand control enable/power, peak shaving and valley filling power control, peak and valley power registers (3907–3913) (2024.06.03)
• V2.8 – Added Self-Consumption Charge Start Time 02 (2024.06.17)
• V2.9.01 – Added Time of Use 3-5 (2024.07.21)