KROHNE C95 CI EN - Manual (Page 31)

S
0 0 0 0 0 0 0 0
byte 3
0 0 0 0 0 0 0 0
byte 4
0 0 0 1 0 0 11
byte 1
1 0 0 0 0 111
byte 2
0 0 0 0 0 0 0 0
byte 3
0 0 0 0 0 0 0 0
byte 4
0 0 0 1 0 0 11
byte 1
1 0 0 0 1 0 0 0
byte 2
0 0 19 136
Plus 1
Invertion
Measure = -(byte 3 x 2563 + byte 4 x 2562+ byte 1 x 256+ byte 2)
= -( 0 x 2563 + 0 x 2562 + 19 x 256 + 136)
= - 5000
Reading of address 120 =>decimal point = 2 =>displayed meas. -50.00
9.4 CRC 16 calculation algorythm :
FFFF → CRC
CRC ⊕ BYTE → CRC
FIN
yes no
n = 0
n = n + 1
yes no
shifting by 1 bit to the
right of CRC
carry
CRC ⊕ poly → CRC
n > 7
next byte
yes
no
Note 1 : ⊕ = exclusive or.
Note 2 : POLY = A001 (hex).
Note 3 :
The CRC16 calculation applies to all bytes in the pattern (except CRC16).
Note 4 :
Caution ! In the CRC 16, the 1st sent byte is the LSB.
Example : Pattern 1-3-0-75-0-2 CRC16 = 180-29 (values are decimal).
end of pattern