DRAND

DRAND 1:

The function block permits generation of a (pseudo-) random number of type LREAL.

DRAND 2: Inputs

VAR_INPUT
    Seed : INT;
END_VAR

Name

Type

Description

Seed

INT

Initial value for specification of the random number series.

DRAND 3: Outputs

VAR_OUTPUT
    Num : LREAL;
END_VAR

Name

Type

Description

Num

LREAL

This output returns a pseudo-random number in the range 0.0 ... 1.0 with double accuracy. The generator here creates a number series with 1075 stochastic values per period.

Example of the function block in FBD:

DRAND 4:

In the example the LREAL value 0.643412 is generated and returned. The input parameter Seed affects the initial value of the series. If, for instance, a deterministically reproducible random number series is desired in different sessions, and identical Seed value must be used.

Requirements

Development environment

Target system type

PLC libraries to include (Category group)

TwinCAT v3.1.0

PC or CX (x86, x64, ARM)

Tc2_System (System)