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Processing Character Strings
Section 5-1
5-1 Processing Character Strings
Example The following code will find the position of “STX” in response data R$, retrieve
the characters from there to “ETX” and store them in A$.
Example If the two characters after the fourth character from the start of response data
A$ are 00, The following line will jump to line 1000 as a correct response.
5-2 Processing Bits
Note 1. One bit will be set without changing the other bits.
2. When transferring bit data to the PC, turn ON/OFF the required bit with
these commands and then use the PC PUT command.
5-3 Processing Receive Buffers
Process Programming
Retrieving n characters from beginning of
A$ B$ = MID$(A$, 1, n) or
B$ = LEFT$(A$, n)
Retrieving n characters from character
number m B$ = MID$(A$, m, n)
Retrieving n characters from end of A$ B$ = RIGHT$(A$, n)
Searching for character string from char-
acter number m in A$ and getting position
of first character B = INSTR(m, A$, character_string )
Getting number of characters in A$ B = LEN(A$)
Converting character string A$ to numeric
value B = VAL(A$)
Converting numeric value B to character
string A$ A$ = STR$(B)
100 STX$ = CHR$(&H02) Generate STX.
110 ETX$ = CHR$(&H03) Generate ETX.
120 A = INSTR(1, R$, STX$) Find the position of STX$ in R$.
130 B = INSTR(1, R$, ETX$) Find the position of ETX$ in R$.
140 A$ = MID$(R$, A, B–A+1) Retrieve the character string from STX$ to
ETX$ in R$ and store it in A$.
150 IF MID$(A$,4,2)=“00” THEN 1000
Process Programming
Turning ON/OFF 1 bit of a variable. BITON A%, 3
(Turns ON bit 3 of variable A%.)
BITOFF A%, 3
(Turns OFF bit 3 of variable A%.)
Process Programming
Obtaining the number of characters in the
receive buffer A = LOC(1)
(Stores the number of characters held in
the communications port #1 receive
buffer in A.)
Executing a process if the number of
characters in a receive buffer is not 0
(i.e.,if it is not empty)
100 A = LOC(1)
110 IF A<>0 THEN 200
200
Process A