Description

Function description

With this function block the input signal is delayed by a deadtime.

The function block delays the signal IN by the deadtime T_DELAY, before it is transmitted to OUT again.

The function block has a delay puffer for 128 elements (IN values), i.e. 128 IN values can be saved during the T_DELAY time. The buffer is used in such a way that it corresponds with the operating mode.

Whether the system is started cold or warm, the value of OUT remains unchanged. The internal values are set to the value of IN.

After a change of deadtime T_DELAY or a cold or warm system start, the output READY goes to "0". This means: that the buffer is empty and not ready.

The function block has both a tracking and automatic mode.

NOTE: This function block performs an internal initialization in the first program cycle after a warm start or cold start (e.g. application download or power cycle) of the PLC program.

Due to this, you have to make sure that the function block is invoked in the first program cycle. In case of inkoving the function block in a later program cycle, the internal initialization will not be performed and the ouputs may deliver wrong values.

WARNING

UNEXPECTED OUTPUT BEHAVIOUR

Make sure that the function block is always invoked in the first program cycle.

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

and can be configured as additional parameters.

Representation in FBD

Representation:

Representation in LD

Representation:

Representation in IL

Representation:

CAL QDTIME_Instance (IN:=InputValue, T_DELAY:=DeadTime,
    TR_I:=InitializationInput, TR_S:=InitializationType,
    OUT=>Output, READY=>InternalBufferFlag)

Representation in ST

Representation:

QDTIME_Instance (IN:=InputValue, T_DELAY:=DeadTime,
    TR_I:=InitializationInput, TR_S:=InitializationType,
    OUT=>Output, READY=>InternalBufferFlag) ;

QDTIME parameter description

Description of input parameters:

Parameter	Data type	Description
IN	REAL	Input value
T_DELAY	TIME	Deadtime
TR_I	REAL	Initialization input
TR_S	BOOL	Initialization type: "1" = Operating mode Tracking "0" = Automatic operating mode

Description of output parameters:

Parameter	Data type	Description
OUT	REAL	Output
READY	BOOL	"1" = internal buffer is full "0" = internal buffer is not full (e.g. after warm/cold start or alteration to deadtime)

Runtime error

For a list of all block error codes and values, see Conditioning.

REAL

The REAL type is encoded in a 32 bit format.

The possible value ranges are shown in the figure below:

When a result is:

between -1,175494e-38 and 1,175494e-38, it is considered to be a DEN;
less than -3.402824e+38, the symbol -INF (for - infinity) is displayed;
greater than +3.402824e+38, the symbol INF (for + infinity) is displayed;
undefined (square root of a negative number), the symbolNAN is displayed.

NOTE: The IEC 559 standard defines two classes of NAN: the silent NAN (QNAN) and the signaling NAN (SNAN). A QNAN is a NAN with a most significant fraction bit while an SNAN is a NAN without a most significant fraction bit (bit number 22). QNANs can be propagated via most arithmetic operations without throwing an exception. As for SNANs, they generally indicate n invalid operation when they are used as operands in arithmetic operations (see %SW17 and %S18).

NOTE: When a DEN (non-standardized number) is used as an operand, the result is not significant.