F118_UDC

UP/DOWN counter

DOWN counting if the trigger UpDirection is in the OFF state. UP counting if the trigger UpDirection is in the ON state.

Parameters

Input

UpDirection (BOOL): sets counter to count up (ON) or down (0FF)
CountTrigger (BOOL): starts counter
Reset_Preset (BOOL): resets counter
s_PresetValue (WORD, INT, UINT): 16-bit area or equivalent constant for counter preset value

Output

d (WORD, INT, UINT): 16-bit area for counter elapsed value

Remarks

The area for the elapsed value d becomes 0 when the rising edge of the trigger is detected (OFF ® ON). The value in s_PresetValue is transferred to d when the falling edge of the trigger is detected (ON ® OFF).
The variables s_PresetValue and d have to be of the same data type.

Example

POU header

All input and output variables used for programming this function have been declared in the POU header. The same POU header is used for all programming languages.

	VAR
		up: BOOL:=FALSE;
			(*declares, if the counter
counts up or down*)
		count: BOOL:=FALSE;
			(*at a rising edge on count
the counter counts*)
		reset: BOOL:=FALSE;
			(*resets the counter to 
set_value if TRUE*)
		set_value: INT:=0;
			(*the starting value*)
		output_value: INT:=0;
			(*the actual value*)
	END_VAR

POU body

A rising edge at the input Count_Trigger activates the counter. The boolean variable at the input UpDirection sets the direction of the counter (TRUE = up, FALSE =down). TRUE at the input Reset_Preset resets the counter to the starting value.

LD body

BODY
    WORKSPACE
        NETWORK_LIST_TYPE := NWTYPELD ;
        ACTIVE_NETWORK := 0 ;
    END_WORKSPACE
    NET_WORK
        NETWORK_TYPE := NWTYPELD ;
        NETWORK_LABEL :=  ;
        NETWORK_TITLE :=  ;
        NETWORK_HEIGHT := 6 ;
        NETWORK_BODY
B(B_F,F118_UDC!,Instance,8,0,17,6,,?DUpDirection?DCountTrigger?DReset_Preset?Ds_PresetValue?Cd);
B(B_VARIN,,up,6,1,8,3,);
B(B_VARIN,,count,6,2,8,4,);
B(B_VARIN,,reset,6,3,8,5,);
B(B_VARIN,,set_value,6,4,8,6,);
B(B_VAROUT,,output_value,17,1,19,3,);
L(1,0,1,6);
        END_NETWORK_BODY
    END_NET_WORK
END_BODY

ST body

output_value:=F118_UDC( UpDirection:= up, Count_Trigger:= count, Reset_Preset:= reset, s_PresetValue:= set_value);
(* output_value contains the count value *)