Appendix B: - Operands in CoDeSys
END_STRUCT
END_TYPE
Declaration in POU:
VAR x:stru1; END_VAR
Bitaccess:
x.enable:=true;
This will set TRUE the 42. bit in variable x. Since bvar has 8 bits and rvar has 32 bits, the bitaccess will be done on the second bit of variable wvar, which as a result will get value 4.
Attention: If a variable, which does a bitaccess on a structure variable with the aid of a global constant, should be displayed correctly in the input assistant, at monitoring in the declaration window and in the intellisense function, please use pragma {bitaccess} as shown in the example. Then in addition you get displayed the global constant beyond the respective structure variable during monitoring in the declaration window:
10.12 Addresses
Address
The direct display of individual memory locations is done through the use of special character sequences. These sequences are a concatenation of the percent sign "%", a range prefix, a prefix for the size and one or more natural numbers separated by blank spaces.
The following range prefixes are supported:
I Input
Q Output
M Memory location
The following size prefixes are supported:
X Single bit
None Single bit
B Byte (8 Bits)
W Word (16 Bits)
D Double word (32 Bits)
CoDeSys V2.3 |
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|
Appendix B: - Operands in CoDeSys |
Examples: |
|
%QX7.5 and |
Output bit 7.5 |
%Q7.5 |
|
%IW215 |
Input word 215 |
%QB7 |
Output byte 7 |
%MD48 |
Double word in memory position 48 in the memory location. |
%IW2.5.7.1 |
depending on the PLC Configuration |
The current PLC Configuration for the program determines whether or not an address is valid.
Note: Boolean values will be allocated bytewise, if no explicit single-bit address is specified. Example: A change in the value of varbool1 AT %QW0 affects the range from QX0.0 to QX0.7.
see also Chapter Appendix A: IEC Operators and additional norm extending functions, address operators
Memory location
You can use any supported size to access the memory location.
For example, the address %MD48 would address bytes numbers 192, 193, 194, and 195 in the memory location area (48 * 4 = 192). The number of the first byte is 0.
You can access words, bytes and even bits in the same way: the address %MX5.0 allows you to access the first bit in the fifth word (Bits are generally saved wordwise).
see also Appendix A: IEC Operators and additional norm extending functions, address operators
10.13 Functions
In ST a function call can also appear as an operand.
Example:
Result := Fct(7) + 3;
TIME()-Function
This function returns the time (based on milliseconds) which has been passed since the system was started.
The data type is TIME.
Example in IL:
TIME
ST systime (* Result e.g.: T#35m11s342ms *)
Example in ST:
systime:=TIME();
Example in FUP:
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CoDeSys V2.3 |