Description

Description of the function

The PL7_COUNTER function block is a counter/down counter that allows counting of pulses up or down.

The additional parameters and can be configured.

NOTE: you cannot instantiate or modify the PL7_COUNTER function in online mode. This means you must be in offline mode and therefore you must transfer the project in the PLC.

NOTE: If you create more than 255 instances of PL7_COUNTER the application cannot be transfered in the PLC.

FBD representation

Representation:

LD representation

Representation:

IL representation

Representation:

CAL Counter_1(R := Raz, P := Preselect, CU := Count_Up, CD := Count_Down, E => Empty, D => Done, F => Full)

ST representation

Representation:

IF Raz THEN

   RESET_PL7_COUNTER (Counter_1) ;

END_IF ;

IF Preselect THEN

   PRESET_PL7_COUNTER (Counter_1) ;

END_IF ;

IF Count_Up THEN

   UP_PL7_COUNTER (Counter_1) ;

END_IF ;

IF Count_Down THEN

   DOWN_PL7_COUNTER (Counter_1) ;

END_IF ;

Empty := Counter_1.E ;

Done := Counter_1.D ;

Full := Counter_1.F ;

Description of parameters

The following table describes the input parameters:

Parameter	Type	Comment
R	BOOL	Input of reset to zero, if Counter_1.R is equal to 1, the current value of the counter Counter_1.CV = 0
P	BOOL	Preset input, if Counter_1.S equals 1, Counter_1.CV = Counter_1.PV
CU	BOOL	Count input, the current value is incremented by 1 on the rising edge of Counter_1.CU.
CD	BOOL	Down-count input, the current value is decremented by 1 on the rising edge of Counter_1.CD.

The following table describes the output parameters:

Parameter	Type	Comment
E	BOOL	Empty counter output. Counter_1.E=1 when Counter_1.CV changes from 0 to 9999 and then to 0 again if the counter continues to count down.
D	BOOL	Output which indicates that the counter has reached the preset value. Counter_1.CD = 1 when Counter_1.CV = Counter_1.PV.
F	BOOL	Full counter output. Counter_1.F = 1 when Counter_1.CV changes from to 9999 to 0 and then to 0 again if the counter continues to count up.

Description of variables

The following table describes the public variables:

Parameter	Type	Comment
CV	INT	Current value of counter. This value can be read and tested but not written by the program.
PV	INT	This value, which is between 0 and 9999, is known as the counter preset value. It can be written, read and tested by the program; the default setting is 9999.