[old horse of industrial control] detailed explanation of Siemens PLC s7-300scl programming

SCL Programming details

One ． data type ：

notes ： There are also two types ：P:POINTER( Pointer data type ).A:ANY( Any kind of )

Definition of array ：M1:ARRAY[n0…m0,n1…m1] OF INT;

Two ． Addressing
○1 Absolute addressing

○2 Symbolic addressing
Such as ：DB10.setpoint
“motor1data”.DW12

○3 Indirect addressing
Such as ：E[byteindex,bitindex]
MB[byteindex]
DB10.DW[byteindex]

3、 ... and ．SCL Operators and Expressions

notes ： The expressions of the above operators are basically the same as our mathematical expressions . I'll just explain it here AND,XOR,OR Instructions .

Such as ：a1:=a1 AND W#16#FFFF
a1:=a1 XOR W#16#FFFF
a1:=a1 OR MW10

Four ． Control statement

Be careful ： When using the program loop , Please ensure that the cycle monitoring time is not exceeded .

1. IF sentence :
   IF Conditions 0
   THEN sentence 0;
   ELSIF Conditions 1
   THEN sentence 1;
   ELSIF Conditions 2
   THEN sentence 2;
   ELSE sentence 3;
   END_IF;

2. CASE sentence ：“ choice ” The value in is equal to Const The values in the execute that statement . Other statements are not executed , Is executed END_CASE;
   CASE choice OF
   Const1: sentence 1;
   Const2: sentence 2;
   ………
   Constn: sentence n;
   END_CASE;

3. FOR sentence
   FOR Variable ：=n0 TO n BY m DO
   ……………………;
   ………………….;
   END_FOR;
   Be careful ： there n Is an integer variable or integer value .m Add a few... To each cycle .

4. WHILE sentence ： As long as the conditions are met , The program loop repeats .
   WHILE Conditions DO
   sentence ;
   END_WHILE;

5. REPEAT sentence ： As long as the conditions are not met , Just repeat the program cycle .
   REPEAT
   sentence ;
   UNTIL Conditions ;
   END_REPEAT;

6. CONTINUE sentence ： stay FOR, WHILE, REPEAT Terminates the current program channel in the loop .

7. EXIT sentence ： stay FOR, WHILE, REPEAT Terminate all program channels in the loop .

8. RETURN sentence : Statement unconditionally exits the currently executing block .

9. GOTO sentence ：
   example ：
   LABEL // Define Tags
   M1,M2,M3,END;
   END_LABEL;
   ………………
   CASE Selection;
   1:GOTO M1;
   2:GOTO M2;
   3:GOTO M3;
   ELSE GOTO DND;
   END_CASE;
   M1: sentence 1;
   GOTO DND;
   M2: sentence 2;
   GOTO DND;
   M3: sentence 3;
   END: ;

5、 ... and ． Constant :

1. Bit constant ： The value is TRUE perhaps FALSE.

2. character constants ：( Here is a character )
   Charac_1:=’B’
   Charac_2:=char#43;
   Charac_3:=char#’B’ // character ‘B’
   Charac_4:=’$41’ // character ‘A’

3. String constant ：
   M1:=’ABCDEFJH’

4. Date constant ：
   T1:=DATE#1995-11-11;
   T2:=D#1995-11-11

5. Time constant
   N1:=TIME#10.2S;
   N2:=T#3D_2S_3MS;

6. TIME_OF_DAY Constant ：
   TM1:=TIME_OF_DAY#12:11:10.1;
   TT2:=TOD#10:10:10;

7. DATE_AND_TIME Constant ：
   TT:=DT#2012-4-26-18:12:00;

6、 ... and ． Timers and counters :

1. The timer has 5 Kind of , In turn ：S_PULSE S_PEXT S_ODT S_ODTS S_OFFDT
VAR
CurrTime : S5time;
BiVal : word;
ActFlag : bool;
END_VAR
// When calling the timer , Some parameters can be omitted , But the assignment variable on the left must not be omitted .
CurrTime:=S_ODT(T_N=T10, // Absolute call , Set the timer number
S:=TRUE, // Set condition
TV:=T#1s, // Set the timer value
R:=FALSE, // Reset condition
BI:=biVal,
Q:=actFlag);
FUNCTION_BLOCK TIME
VAR_INPUT
MY_TIMER: ARRAY [1…4] of STRUCT
T_N INT;
TV : WORD;
END_STRUCT;
…
END_VAR
…
FOR I:= 1 TO 4 DO
CurrTime:= S_ODT(T_N=MY_TIMER.T_NO, S:=true,
MY_TIMER.TV);
END_FOR;

FUNCTION_BLOCK TIMER
VAR_INPUT
mytimer:TIMER;
END_VAR
…
CurrTime:=S_ODT(T_N=mytimer,…);

2、 Counter
S_CU Increment counter
S_CD Minus counter
S_CUD increase / Minus counter

e.g.
S_CUD (C_N=C12, // Absolute call timer , Specify the counter number
CD:=I0.0,
CU:=I0.1,
S:=I0.2 & I0.3, // Set condition
PV:=120, // Set the counter value
R:=FALSE, // Reset condition
CV:=binVal, // Output parameters , Binary count value
Q:=actFlag); // Output parameters , Status of the counter
FUNCTION_BLOCK COUNT
VAR_INPUT
Count: ARRAY [1…4] of STRUCT
C_N INT;
PV : WORD;
END_STRUCT;
…
END_VAR
…
FOR I:= 1 TO 4 DO // Dynamic call counter
S_CD(C_N=Count.C_NO, S:=true, PV:= Count.PV);
END_FOR;
FUNCTION_BLOCK COUNTER
VAR_INPUT
MYCounter:COUNTER;
END_VAR
…
CurrVal:=S_CD(C_N=MyCounter,…); // Dynamic call counter

7、 ... and ． Mathematical functions ：
Trigonometric functions Logarithmic function
SIN sine EXP With e Index function for the bottom
COS cosine EXPD With 10 Index function for the bottom
TAN tangent LN Natural logarithm
Anti trigonometric function LOG With 10 Log base
ASIN Anti sine Other mathematical functions
ACOS Arccosine ABS Find the absolute value
ATAN Anyway SQR Find the square
SQRT take a square root

Example ：
RESULT := ABS (-5) ; //5
RESULT := SQRT (81.0); //9
RESULT := SQR (23); //529
RESULT := EXP (4.1); //60.340 …
RESULT := EXPD (3); //1_000
PI := 3. 141 592 ;
RESULT := SIN (PI / 6) ; //0.5

8、 ... and ． Shift function ：
ROL、ROR、SHL、SHR
Example ：
RESULT := ROL (IN:=CRC, N:=5); //CRC , Move left 5 position , The removed fill to the right space
RESULT := ROR (IN:=BYTE#2#1101_0011, N:=2); //2#1111_0100 , Move right 2 position , The removed fill to the left space
RESULT := SHL (IN:=BYTE#2#1101_0011, N:=3); //2#1001_1000 , Move left 3 position , For the spare part 0 fill
RESULT := SHR (IN:=BYTE#2#1101_0011, N:=2); //2#0011_0100 , Move right 2 position , For the spare part 0 fill

Nine ．SCL block
SCL The block structure used is in exactly the same way as standard programming languages .
Be careful ： No function returned by function value FC yes VOID data type .

Ten ． example ：
1. Sort
FUNCTION FC4:VOID
Know_How_Protect

VAR_TEMP
// Temporary Variables
loop_count:INT;
index_1:INT;
index_2:INT;
Data_Store:ARRAY[0…5] OF INT;
T :INT;
N :INT;
END_VAR

// Statement Section

// Block Parameters

VAR_INPUT // Input Parameters
INT0:INT;
INT1:INT;
INT2:INT;
INT3:INT;
INT4:INT;
INT5:INT;

END_VAR

VAR_IN_OUT
// I/O Parameters
END_VAR

VAR_OUTPUT
// Output Parameters
min_data:INT;
l_0,l_1,l_2,l_3,l_4,l_5: INT;
END_VAR

Data_Store[0]:=INT0;
Data_Store[1]:=INT1;
Data_Store[2]:=INT2;
Data_Store[3]:=INT3;
Data_Store[4]:=INT4;
Data_Store[5]:=INT5;

min_data:=Data_Store[0];
N:=0;
T:=0;

FOR loop_count:=0 TO 5 BY 1 DO
// Find minimum
IF min_data > Data_Store[loop_count] THEN min_data:=Data_Store[loop_count];
END_IF;
END_FOR;

FOR index_1:=0 TO 5 BY 1 DO
FOR index_2:=index_1 TO 5 BY 1 DO
IF Data_Store[index_1] < Data_Store[index_2] THEN
T:=Data_Store[index_2];
Data_Store[index_2]:=Data_Store[index_1];
Data_Store[index_1]:=T;
END_IF;
END_FOR;
END_FOR;

l_0:=Data_Store[0];
l_1:=Data_Store[1];
l_2:=Data_Store[2];
l_3:=Data_Store[3];
l_4:=Data_Store[4];
l_5:=Data_Store[5];
END_FUNCTION

2. seek RTU To verify ：
FUNCTION FC101 : VOID
//RTU signal communication SCL Program
// Block Parameters
VAR_INPUT
// Input Parameters
ZH:BYTE;// Station No
GNM:BYTE;// Function code
SZDZ1:BYTE;// Data address 1
SZDZ2:BYTE;// Data address 2
SZNR1:BYTE;// The data content 1
SZNR2:BYTE;// The data content 2
END_VAR

VAR_IN_OUT
// I/O Parameters
END_VAR

VAR_OUTPUT
// Output Parameters
SCZH:BYTE;// Station No
SCGNM:BYTE;// Function code
SCSZDZ1:BYTE;// Data address 1
SCSZDZ2:BYTE;// Data address 2
SCSZNR1:BYTE;// The data content 1
SCSZNR2:BYTE;// The data content 2
XYM1:BYTE;// To verify 1
XYM2:BYTE;// To verify 2
END_VAR

VAR_TEMP
// Temporary Variables
CRC:WORD;
SHUZU:ARRAY[0…7]OF BYTE;// Array
N:INT;// Outer loop 6 Time
M:INT;// Inner loop 8 Time
ZZ:INT;// Array pointer
YCW:WORD;//CRC When shifting right , Judge the last .
TEM:WORD;// Used as a CRC The final result is high 8 Bit and low 8 Separate transmission of bits .

END_VAR
BEGIN
// Statement Section
ZZ:=0;// Clear the pointer
TEM:=0;// Zero clearing

SHUZU[0]:=ZH;// Send the entered station number to the array 0 position
SHUZU[1]:=GNM;// Send the entered function code to the... Of the array 1 position
SHUZU[2]:=SZDZ1;// The data address to be entered 1 To the array 2 position
SHUZU[3]:=SZDZ2;// The data address to be entered 2 To the array 3 position
SHUZU[4]:=SZNR1;// The data content to be entered 1 To the array 4 position
SHUZU[5]:=SZNR2;// The data content to be entered 2 To the array 5 position
CRC:=W#16#FFFF;// take 16#FFFF Send CRC register

FOR N:=0 TO 5 BY 1 DO// Outer loop 6 Time
CRC:=CRC XOR SHUZU[ZZ];// take CRC Register and bytes exclusive or
FOR M:=0 TO 7 BY 1 DO// Inner loop 8 Time
YCW:=CRC;// take CRC The contents of the register are sent to YCW in
YCW:=YCW AND W#16#0001;
// take CRC The last bit of the register , That is, the overflow bit of the following shift
CRC:=SHR(IN:=CRC,N:=1);// Yes CRC Shift the register one bit to the right

IF YCW=W#16#0001 THEN CRC:=CRC XOR W#16#A001;
// Determine whether the overflow bit is 1, yes １ will CRC Register and 16＃A001 Exclusive or .
END_IF;

END_FOR;
ZZ:=ZZ+1; // One byte is processed , Array pointer plus １.
END_FOR;
TEM:=CRC;// take CRC Content in to TEM
TEM:=TEM AND W#16#00FF;// take TEM（CRC） It's low ８ position
SHUZU[6]:=WORD_TO_BYTE(TEM);// take TEM low ８ Bit to array ６ No. A
TEM:=CRC;// then CRC Content in to TEM
TEM:=TEM AND W#16#FF00;// take TEM（CRC） The height of ８ position
TEM:=SHR(IN:=TEM,N:=8);// Re high ８ Shift right ８ position
SHUZU[7]:=WORD_TO_BYTE(TEM);// Will be high ８ The contents of bits are sent to the ７ No. A

SCZH:=SHUZU[0];// Output station No
SCGNM:=SHUZU[1];// Output function code
SCSZDZ1:=SHUZU[2];// Output data address １
SCSZDZ2:=SHUZU[3];// Output data address ２
SCSZNR1:=SHUZU[4];// Output data content １
SCSZNR2:=SHUZU[5];// Output data content ２
XYM1:=SHUZU[6];// Output validation code
XYM2:=SHUZU[7];// Output validation code

END_FUNCTION