Argo-Hytos OPCom - Checksum Calculation (CRC)

Subject to change · V 2.02.20 · EN
Page 41
www.argo-hytos.com
Response Significance (decimal) according to ASCII-Table
M 77
e 101
m 109
S 83
: 58
3 51
0 48
7 55
2 50
[ 91
- 45
] 93
; 59
C 67
R 82
C 67
: 58
? 63
[CR] 13
[LF] 10
Sum
1280  1280 / 256 = 5 Rest 0  Error-free transmission
„RMemS[CR]“
„MemS:3072;CRC:?[CR][LF]“
Fig. 24: Example data transmission RS232 with checksum
Table 23: Example checksum calculation (CRC)
15.4 Checksum calculation (CRC)
To check if the response to the command was transmitted error-free, the checksum (CRC) can be used.
The decimal value of each character sent in a string (see ASCII-table) has to be added up. Including Line feed [LF] and Carriage
Return [CR]. If the result is dividable through 256, the transmission is error-free.
An example of the response of the OPCom to the command „RMemS[CR]“ is shown below. (Reading out the memory usage)