Description

Description of the function

The PL7_DRUM function block is a drum. Each step is associated with output bits or internal bits known as order bits. This function block is used to convert PL7 programs; it corresponds to the conversion of the %DRi’s under PL7.

The additional parameters and can be configured.

NOTE: you cannot instantiate or modify the PL7_DRUM 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_DRUM the application cannot be transfered in the PLC.

FBD representation

Representation:

LD representation

Representation:

IL representation

Representation:

CAL PL7_Drum_1(R := Raz, U := Up, F => Full, W => %MW0)

ST representation

Representation:

IF Raz THEN

   RESET_PL7_DRUM(PL7_Drum_1);

END_IF ;

IF RE (Up) THEN

   UP_PL7_DRUM(PL7_Drum_1);

END_IF ;

Full := PL7_Drum_1.F ;

%MW0 := PL7_Drum_1.W ;

Description of parameters

The following table describes the input parameters:

Parameter	Type	Comment
R	BOOL	"Return to step 0" input, at state 1 initializes the drum at step 0.
U	BOOL	"Advance" input, on rising edge causes the drum to advance by one step and the updating of the order bits.

The following table describes the output parameters:

Parameter	Type	Comment
F	BOOL	Output indicating that the final step defined is in progress.
W	INT	Current step output value.

Description of variables

The following table describes the public variables:

Parameter	Type	Comment
LEN	UINT	Number of steps: possible values from 1 to 16 (default is 16).
ET	INT	Time out or duration of current step. PL7_Drum_1.ET is between 0 and 9999. This integer can be reset to zero for each step change. It can be read and tested, but not written. The duration of a step is equal to PL7_Drum1.ET x PL7_Drum_1.TB.
S	INT	Between 0 and 15, this is the number of the current step. This integer can be read and tested. It can only be written from an immediate value.
TB	UINT	Cyclical programmer time base. Possible values: TB = 8: 1 mn (default value), TB = 4: 1 s, TB = 2: 100 ms, TB = 1: 10 ms. When the program is executed, the value of the time base (TB defined in offline mode) is rounded down to the nearest multiple of 2 (between 1 and 8).
W0...Wj (j=LEN-1)	INT	PL7_Drum_1.Wj is a word representing the state of step j. This word (type INT) indicates the state of each order bit for a given step. It is entered by the user using the data editor. Note: There are as many Wj as there are steps (LEN).

CAUTION

UNEXPECTED BEHAVIOR AFTER WARM RESTART

Do no modify the time base (TB) in online mode, this would cause an unexpected behavior of the application on warm restart.

Failure to follow these instructions can result in injury or equipment damage.

Chart

Chart of the operation of the PL7_DRUM function block:

The number of the current step is incremented for each rising edge on the input PL7_Drum_1.U (or activation of the instruction UP_PL7_DRUM(PL7_Drum_1)). This number can be changed by the program.