Description

Function description

The DTIME function block generates a delay when transfering the numerical input value [IN]. The numerical output variable OUT generates the same behavior as the numerical input value when the delay T_DELAY, which can vary, is included.

Behavior of the function block DTIME:

and can be configured as additional parameters.

Formula

This function block implements the following transfer function :

Representation in FBD

Representation:

Representation in LD

Representation:

Representation in IL

Representation:

CAL DTIME_Instance (IN:=ValueToDelay, 
    T_DELAY:=RequiredDelay, TR_I:=InitializationInput, 
    TR_S:=InitializationSequence, OUT=>DelayedOutput, 
    BUFFER=>DelayValueBuffer, STATUS=>StatusWord)

Representation in ST

Representation:

DTIME_Instance (IN:=ValueToDelay, 
    T_DELAY:=RequiredDelay, TR_I:=InitializationInput, 
    TR_S:=InitializationSequence, OUT=>DelayedOutput, 
    BUFFER=>DelayValueBuffer, STATUS=>StatusWord) ;

Parameter description

Input parameter description:

Parameter	Data type	Meaning
IN	REAL	Numerical value to delay
T_DELAY	TIME	Desired delay
TR_I	REAL	Initialization input
TR_S	BOOL	Initialization command

Output parameter description:

Parameter	Data type	Meaning
OUT	REAL	Delayed output
BUFFER	ANY*)	Memory for the purpose of storing delayed values.
STATUS	WORD	Status word

*) It is essential for this to be linked to a variable (see"Parametering").

EN stands for ENable; it is an optional block input. When the EN input is enabled, an ENO output is set automatically.

If EN = 0, the block is not enabled; its internal program is not executed, and ENO is set to 0.

If EN = 1, the block's internal program is run and ENO is set to 1. If an error occurs, ENO is set to 0.

If the EN input is not connected, it is set automatically to 1.

ENO

ENO stands for Error NOtification; this is the output associated with the optional input EN.

If ENO is set to 0 (because EN = 0 or in case of an execution error):

the status of the function block outputs remains the same as it was during the previous scanning cycle that executed correctly;
the output(s) of the function, as well as the procedures, are set to "0".

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.

TIME

The TIME type expresses a time in milliseconds. Encoded in 32 bits, this type can be used to obtain times from 0 to 2 32-1 milliseconds.

The TIME type has the following units: days (d), hours (h), minutes (m), seconds (s) and milliseconds (ms). A literal value of type TIME is represented by a combination of the preceding types prefixed with T#, t#, TIME# or time#.

Examples: T#25h15m, t#14,7S, TIME#5d10h23m45s3ms