A function block groups an algorithm and a set of private data. It has inputs and outputs. - Down-counting stop watch.
Inputs
IN : BOOL The time counts when this input is TRUE
RST : BOOL Timer is reset to PT when this input is TRUE
PT : TIME Programmed time
Outputs
Q : BOOL Timer elapsed output signal
ET : TIME Elapsed time
Time diagram
Remarks
The timer counts up when the IN input is TRUE. It stops when the programmed time is elapsed. The timer is reset when the RST input is TRUE. It is not reset when IN is false.
ST Language
(* MyTimer is a declared instance of TMD function block *)
MyTimer (IN, RST, PT);
Q := MyTimer.Q;
ET := MyTimer.ET;
FBD Language
FFLD Language
IL Language
(* MyTimer is a declared instance of TMD function block *)
Op1: CAL MyTimer (IN, RST, PT)
FFLD: MyTimer.Q
ST "Structured text"
A high-level language that is block structured and syntactically resembles Pascal: Q
FFLD: MyTimer.ET
ST: ET
See also
