# Backlash (G Dataflow)

Last Modified: January 12, 2018

Implements a backlash or deadband function.

## reset

A Boolean or a Boolean array that determines whether to use initial output to perform the deadband computation.

 True Uses initial output to perform the deadband computation. False Uses the previous output to perform the deadband computation.

This node automatically uses initial output to perform the deadband computation on the first call.

Default: False

## input

Input signal.

This input accepts a double-precision, floating-point number or an array of double-precision, floating-point numbers.

## deadband

Width of the deadband.

This input accepts a double-precision, floating-point number or an array of double-precision, floating-point numbers.

Default: 0

## initial output

Value that this node compares with input the first time the backlash function executes or when reset is True.

This input accepts a double-precision, floating-point number or an array of double-precision, floating-point numbers.

Default: 0

## output

Output signal.

This output can return a double-precision, floating-point number or an array of double-precision, floating-point numbers.

## Algorithm Definition for the Backlash Function

The following equation defines the backlash function.

$y\left(t\right)=\left\{\begin{array}{c}y\left(t-1\right)\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\mathrm{if}\text{\hspace{0.17em}}|u\left(t\right)-y\left(t-1\right)|\le \frac{deadband}{2}\\ u\left(t\right)-\frac{deadband}{2}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\mathrm{if}\text{\hspace{0.17em}}|u\left(t\right)-y\left(t-1\right)|\le \frac{deadband}{2}\text{\hspace{0.17em}}\mathrm{and}\text{\hspace{0.17em}}u\left(t\right)>y\left(t-1\right)\text{\hspace{0.17em}}\\ u\left(t\right)+\frac{deadband}{2}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\text{\hspace{0.17em}}\mathrm{if}\text{\hspace{0.17em}}|u\left(t\right)-y\left(t-1\right)|>\frac{deadband}{2}\text{\hspace{0.17em}}\mathrm{and}\text{\hspace{0.17em}}u\left(t\right)\le y\left(t-1\right)\text{\hspace{0.17em}}\end{array}$

where

• u is the input signal
• y is the output signal
• t is the current simulation time

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported

Web Server: Not supported in VIs that run in a web application