ACD320 user manual
Appendix
words)
For example: for an inverter with the slave address of 01H, the start address of memory is
0004, ready consecutive two words, the structure of the frame is as follows:
RTU Command Message of the Master
START
T1-T2-T3-T4 (transmission time of 3.5 bytes)
ADDR
01H
CMD
03H
Higher bits of start address
00H
Lower bits of start address
04H
Higher bits of data number
00H
Lower bits of data number
02H
CRC CHK lower bit
85H
CRC CHK higher bit
CAH
END
T1-T2-T3-T4 (transmission time of 3.5 bytes)
RTU Response Message of the Slave
START
T1-T2-T3-T4(transmission time of 3.5 bytes)
ADDR
01H
CMD
03H
byte number
04H
Higher bits of data address
00H
0004H
Lower bits of data address
00H
0004H
Higher bits of data address
00H
0005H
Lower bits of data address
00H
0005H
CRC CHK lower bit
FAH
CRC CHK higher bit
33H
END
T1-T2-T3-T4（transmission time of 3.5 bytes）
ASCII Command Message of the Master
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