Beijer Electronics AN-BEI-E2-038 - Manual

APPLICATION NOTE AN‐BEI‐E2‐038 Date: 15/02/12
AN‐BEI‐E2‐038 Modbus RTU Control and Register Mapping 1
BFI Applications Support Library
Application Note AN‐BEI‐E2‐038
Title
Modbus RTU Control and Register Mapping
Related Products Beijer Frequency Inverter E2
Level
3
1 – Fundamental ‐ No previous experience necessary
2 – Basic – Some Basic drives knowledge recommended
3 – Advanced – Some Basic drives knowledge required
4 – Expert – Good experience in topic of subject matter recommended
Overview:
Beijer Frequency Inverter E2 drives support Modbus RTU communications, allowing a network of drives to be controlled and
monitored by any Modbus RTU capable PLC or control system. The Beijer Frequency Inverter E2 is always a Slave to an external
Modbus RTU Master. This document describes the registers and functions available.
Modbus RTU Protocol Specification:
Protocol Modbus RTU
Error check CRC
Baud rate 9600bps, 19200bps, 38400bps, 57600bps, 115200bps (default)
Data format 1 start bit, 8 data bits, 1 stop bits, no parity.
Physical signal RS 485 (2‐wire)
User interface RJ11
Modbus Telegram Structure:
The following Modbus Commands are supported
• 03 Read Holding Registers
• 06 Write Single Holding Register
commands. The telegram structure is as follows:‐
Command 03 – Read Holding Registers Command 06 – Write Single Holding Register
Master Telegram Length Slave Response Length Master Telegram Length Slave Response Length
Slave Address 1 Byte Slave Address 1 Byte Slave Address 1 Byte Slave Address 1 Byte
Function Code (03) 1 Byte Starting Address 1 Byte Function Code (06) 1 Byte Function Code (06) 1 Byte
1 st Register Address 2 Bytes 1 st Register Value 2 Bytes Register Address 2 Bytes Register Address 2 Bytes
No. Of Registers 2 Bytes 2 nd Register Value 2 Bytes Value 2 Bytes Register Value 2 Bytes
CRC Checksum 2 Bytes Etc... CRC Checksum 2 Bytes CRC Checksum 2 Bytes
CRC Checksum 2 Bytes