Omron V400-H111 user manual Calculation Programming Example for Sending FCS

Appendices FCS Calculation Method

Appendices

■Calculation Programming Example for Sending FCS

DATA$	Sample data string
L	Data length
CODE$	Data character
A	Exclusive OR

100 ’* * * * * CALCULATE FCS * * * * *

110’* FCSSET

120L=LEN(DATA$)

130A=0

140FOR J=1 TO L

150CODE$=MID$(DATA$,J,1)

160A=ASC(CODE$)XOR A

170	NEXT J
180	FCS$=HEX$(A)
190	IF LEN(FCS$)=1 THEN FCS$=“0”+FCS$

200RETURN

■FCS Check Subroutine Example for Received Data

1000	’* * * * * FCSHECK * * * * *
1010	’* FCSHECK
1020	Q=0:FCSCK$=“OK”
1030	PRINT RESPONSE $
1040	LENGS=LEN(RESPONSE$)-3
1050	FCSP$=MID$(RESPONSE$,LENGS+1,2)	’FCS in response data
1060	FOR J=1 TO LENGS	’Calculation range of FCS
1070	Q=ASC(MID$(RESPONSE$,J,1))XOR Q
1080	NEXT J
1090	FCSD$=HEX$(Q)
1100	IF LEN(FCSD$)=1 THEN FCSD$=“0”+FCSD$	’FCS calculated in a program
1110	IF FCSD$ < > FCSP$ THEN FCSCK$=“ERR”
1120	PRINT “FCSD$=”;FCSD$;“FCSP$=”;FCSP$;	’FCS received correctly: OK
	“FCSCK$=”;“FCSCK$=”	’FCS not received correctly:
		ERR
1130	RETURN

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V400-H111/211

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