PRBS – Pseudo-random binary sequence generator

Block SymbolLicensing group: STANDARD
PIC

Function Description
The PRBS block generates a pseudo-random binary sequence. The figure below displays how the sequence is generated.

PIC

The initial and final values of the sequence are val0. The sequence starts from this value when rising edge occurs at the START input (off on), the output y is immediately switched to the valhi value. The generator then switches the output to the other limit value with the period of swper seconds and the probability of switching swprob. After seqt seconds the output is set back to val0. A waitt-second period follows to allow the settling of the controlled system response. Only then it is possible to start a new sequence. It is possible to terminate the sequence prematurely by the BRK = on input when necessary.

Inputs

START

Starting signal (rising edge)

Bool

BRK

Termination signal

Bool

Outputs

y

Generated pseudo-random binary sequence

Double (F64)

BSY

Busy flag

Bool

Parameters

val0

Initial and final value

Double (F64)

valhi

Upper level of the y output  1.0

Double (F64)

vallo

Lower level of the y output  -1.0

Double (F64)

swper

Period of random output switching [s]  1.0

Double (F64)

swprob

Probability of switching   0.0  1.0 0.2

Double (F64)

seqt

Length of the sequence [s]  10.0

Double (F64)

waitt

Settling period [s]  2.0

Double (F64)

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