E5
−
H High Performance Universal Inverter User Manual
Appendix A Modbus Communication Protocol
115
Appendix A Modbus Communication Protocol
1. Support Protocol
Support Modbus protocol, RTU format, Broadcast address 0, slave address “1
−
247”, “248
−
255” for
reservation.
2. Interface mode
RS485: Asynchronous, half duplex, LSB sending priority. Low byte is after the high byte.
Inverter communication port A (RJ45) default data format: 8
−
N
−
1, 38400 bps
It is recommended to adopt EIA/TIA T568B, the lead of port A is defined as:
Attached Figure 1 RJ45 interface
Lead of
communication
port A
1 2
3
4
5
6
7
8
Signal of
communication
port A
+5V
GND
485+
485
−
485+
485
−
GND
+5V
EIA/TIA T568A
White
green
Green
White
orange
Blue
White
blue
Orange
White
brown
Brown
EIA/TIA T568B
White
orange
Orange
White
green
Blue
White
blue
Green
White
brown
Brown
3. Protocol Format
Attached Figure 2 Protocol Format
ADU (Application Data Unit) check is the CRC16 check of the first three parts of ADU and obtained
through exchange of upper byte or lower byte.
If the operation request is rejected, the feedback of PDU(Protocol Data Unit) will be error code or
abnormal code. Error code equals to function code +0x80, abnormal code shows the error cause in
detail.
Examples for abnormal codes:
1
8