TMD

 Function Block A function block groups an algorithm and a set of private data. It has inputs and outputs. - Down-counting stop watch.

Inputs

Input	Data Type	Range	Unit	Default	Description
IN	BOOL	FALSE, TRUE			The time counts Internal count pulses, 1 pulse = 1/2^20turn. when this input is TRUE.
RST	BOOL	FALSE, TRUE			Timer is reset New start of the microprocessor. to 0 (zero) when this input is TRUE.
PT	TIME				Programmed The act of performing a sequence of instructions or commands. time.

Outputs

Input	Data Type	Range	Unit	Description
Q	BOOL	FALSE, TRUE		Timer elapsed output signal.
ET	TIME			Elapsed time.

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.

Time Diagram

Figure 1: Time Diagram

FBD Language Example

FFLD Language Example

IL Language Example

(* MyTimer is a declared instance of TMD function A function calculates a result according to the current value of its inputs. 
A function has no internal data and is not linked to declared instances. 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

ST Language Example

(* MyTimer is a declared instance of TMD function block *)
MyTimer (IN, RST, PT);
Q := MyTimer.Q;
ET := MyTimer.ET;

See Also

TMU / TMUsec