STDemo sample project

This sample demonstrates the use of programming with ST language.

Important links:
   - ST language
   - Using the ST editor

   - BLINK, F_TRIG and CTU function blocks
   - ANY_TO_BOOL and AND_MASK functions
   - Calling a function block
   - Declaring I/O boards in the variable editor
   - Using defined words

The application is divided into two ST programs. The first "PMAIN" program performs the following operations:

- Chain calls to a BLINK block and a F_TRIG edge detection block so that the rest of the program is executed only once each second.

- The rest of a program is a simple activation of a CTU up-counter function block. The output of the block is reset to 0 when the variable bCommand is FALSE. Counting output is the iValue DINT variable

Note that the blinking period "ThePeriod" is a definition declared globally in the "Global defines" and is equivalent to the "t#1s" constant expression.

The second "ActuateOutput" program performs mask operations so that the 8 lowest bits of the iValue variable are copied to boolean I/O variables.