问西门子PLC与Arduino的串行通信

EN

LEN
CONCAT
LEFT or RIGHT
MID
INSERT
DELETE
REPLACE
FIND
EQ_STRNG and NE_STRNG
GE_STRNG and LE_STRNG
GT_STRNG and LT_STRNG
INT_TO_STRING and
STRING_TO_INT
DINT_TO_STRING and
STRING_TO_DINT
REAL_TO_STRING and
STRING_TO_REAL

temp1_temp:=DELETE(IN1:=inputmsg,IN2:='$AOPT_TEMP1_',L:=12,P:=0);

//result should be "20_TEMP2_21"
//if you have a result above or below a 2 digit number we can't just get 
//the next two chars in the string.  so we use the FIND.

temp1_endpos:=FIND(IN1:=temp1_temp,IN2:='_');
temp1_str:=LEFT(IN1:temp1_temp,L:=temp1_endpos);
Temp1:=string_to_real(temp1_str); 

//work off of the position of the temp1_endpos and the string stored in
//temp1_temp

temp2_str:=RIGHT(IN1:=temp1_temp,LEN(temp1_temp)-temp1_endpos-6);

//working from the right side of the string 
// 20_TEMP2_21
//   ^-------pos 2   temp2_ is another 6 so we subract another 6
//         ^---pos 6
// len was (in this case) 11, we work from the right because we don't 
    // know how many digits each temp may be.

Temp2:=string_to_real(temp2_str);