Maxsine EP3 AC Series, Руководство пользователя

Страница: 201 / 246

6.3 MODBUS communication protocol
191
RTU mode: ：
command information
：
Respond information
：
ADR 01H ADR 01H
CMD 06H CMD 06H
Initial data
position
00H (high byte) initial data
address
00H (high
byte)
05H (low byte) 05H (low
byte)
Data content 00H (high byte) Data content 00H (high
byte)
64H (low byte) 64H (low
byte)
CRC Low 98H (high byte) CRC Low 98H (high
byte)
CRC High 20H (low byte) CRC High 20H (low
byte)
Every operational parameter is only limited to the same parameter section. Different
parameter section needs to be operated respectively.
Frame check calculate of LRC (ASCII mode) and CRC(RTU mode):
LRC frame check:
ASCII mode adopts LRC (Longitudinal Redundancy Check)frame check.LRC
calculation adds all the 8bit character from ADR to the last data content in the message,
neglects carry and then determines its two's complement.(For example, if the result after
adding is 128H in hexadecimal , then take 28H). Then calculate its two's complement. The
counting result is LRC frame check.