Delta Electronics VFD-M Series User Manual page 101

Chapter 4 Parameters|
RTU Mode:
Command message:
Starting data
Number of data
(count by word)
Number of data
(count by byte)
The first data
The second data
CRC Check Low
CRC Check High
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.
Starting data address
Number of data
4-66
ADR
CMD
address
content
content
STX
ADR 1
ADR 0
CMD 1
CMD 0
LRC CHK 1
LRC CHK 0
END 1
END 0
01H
10H
00H
11H
00H
02H
04H
13H
88H
0FH
A0H
B2H
49H
':'
'0'
'1'
'0'
'3'
'0'
'4'
'0'
'1'
'0'
'0'
'0'
'1'
01H+03H+04H+01H+00H+01H=0AH,
'F'
the 2's-complement negation of 0AH is F6H.
'6'
CR
LF
Response message:
ADR
CMD
Starting data
address
Number of data
(count by word)
CRC Check Low
CRC Check High
Revision May 2008, ME14, SW V3.04
01H
10H
00H
11H
00H
02H
11H
CDH