I've got a question about bit addressing in Codesys 2.3.9.18:

I would like to use the following code:

iTest : int;
wTest : word;
FOR iTest := 1 TO 10 DO
   wTest.iTest := TRUE;
END_FOR

This returns the error:
Integer number or symbolic constant expected

The following example does work:

FOR iTest := 1 TO 10 DO
   wTest.1   := TRUE;
END_FOR

Is it possible to use something like 'wTest.iTest'?

(and yes, it is possible to use an ARRAY OF BOOL to store a large collection of booleans, but this uses a lot more memory)

I only could suggest to use a function, which gets the bit number as an input.

http://www.geisler-controls.de I've published the library BinUtils. Use the function PutBit_W out of it :

iTest : int;
wTest : word;
FOR iTest := 1 TO 10 DO
   wTest := PutBit_W (wTest, iTest, TRUE); (* to set the bit iTest *)
   wTest := PutBit_W (wTest, iTest, FALSE); (* to clear the bit iTest *)
END_FOR

This will work.

Thanks for your reply. You put me on the right track. A library I'm already using (util.lib) also has a function PUTBIT. The program works now.

To add you can also use constants as bit modifiers but you also have to select in the OPTIONS-BUILD-REPLACE CONSTANTS. So you can do the following:

options :word;
var constant
 OPTION1 : word := 0;
 OPTION2 : word := 1;
 ON          : BOOL := TRUE;
 OFF         : BOOL := False;
end_var
options.OPTION1 := ON;
options.OPTION2 := OFF;