Omron V600 Series Operation Manual page 33

Command Format
3-3-4 FCS Computation Program Example (V600-CA2A-V
1000 *******FCSCHECK*******
1010 *FCSCHECK
1020 Q=0:FCSCK$="OK"
1030 PRINT RESPONSE$
1040 LENGS=LEN (RESPONSE$)–3
1050 FCSP$=MID$ (RESPONSE$.LENGS+1, 2)
1060 FOR I=1 TO LENGS
1070 Q=ASC (MID$ (RESPONSE$, I, 1) XOR Q
1080 NEXT I
1090 FCSD$=HEX$ (Q)
1100 IF LEN (FCSD$)=1 THEN FCSD$="0"+FCSD$
1110 IF FCSD$<>FCSP$ THEN FCSCK$="ERR"
1120 PRINT "FCSD$="FCSD$, "FCSP$="FCSP$, "FCSCK$="FCSCK$:
1130 RETURN
3-3-5 Data Code Specification
ASCII Code Specification
Example:
@ 0 2 R
Controller Header
@
0
2
R
D
H
1
0
0
0
5
Computation
result
ASCII code
See the test program example (page 50) for an example of an FCS computation
program for transmission. An example of an incoming data FCS check subrou-
tine is given below.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Note In this example, CR (CHR$(13)) is not included in RESPONSE$. To insert it,
change line 1040.
The command needs to include a specification indicating how the data to be
read or written is to be handled, either as ASCII code character data, or as hexa-
decimal code numerical data.
When the data length is set to seven bits using the ID Controller DIP switches
(page 83), this specifies ASCII code, and when the data length is set to eight
bits, this specifies JIS code.
D H 1 0 0
Text
0100 0000
EOR
0000
EOR
0011 0010
EOR
0101 0010
EOR
0100 0100
EOR
0100 1000
EOR
0011 0001
EOR
0011 0000
EOR
0011 0000
EOR
0011 0000
EOR
0011 0101
0010 1000
2 8
. . . . . . . . . . . . . . . . . . . . . . . . . . .
FCS computed by software
. . . . . . . . . . .
Section
∗
0 5 2 8
FCS
Only)
Response data FCS
FCS computation range
OK for correct FCS
. . . .
ERR for in correct FCS
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