Delta Electronics VFD-M - Manual (Page 101)

Chapter 4 Parameters|
4-66 Revision May 2008, ME14, SW V3.04
RTU Mode:
Command message: Response message:
ADR 01H ADR 01H
CMD 10H CMD 10H
Starting data 00H Starting data 00H
address 11H address 11H
Number of data 00H Number of data 00H
(count by word) 02H (count by word) 02H
Number of data
(count by byte)
04H CRC Check Low 11H
The first data 13H CRC Check High CDH
content 88H
The second data 0FH
content A0H
CRC Check Low B2H
CRC Check High 49H
3.5 CHK (check sum)
ASCII mode:
LRC (Longitudinal Redundancy Check) is calculated by summing up, module 256, the
values of the bytes from ADR1 to last data character then calculating the hexadecimal
representation of the 2’s-complement negation of the sum.
For example, reading 1 word from address 0401H of the AC drive with address 01H.
STX ‘:’
‘0’ ADR 1
ADR 0
‘1’
‘0’
CMD 1
CMD 0
‘3’
‘0’
‘4’
‘0’
Starting data address
‘1’
‘0’
‘0’
‘0’
Number of data
‘1’
‘F’ LRC CHK 1
LRC CHK 0
‘6’
CR END 1
END 0
LF
01H+03H+04H+01H+00H+01H=0AH,
the 2’s-complement negation of 0AH is F6H.