#!/usr/bin/perl
use strict;
use warnings;
use XML::Twig;

# build a new file in the output format.
my $Output_file_name = 'testOutput.xml';
my $outRoot = XML::Twig::Elt->new('Motors');

#process input XML data
my $twig = new XML::Twig( twig_roots=>{ Sheet=>\&motors } );
$twig->parse(*DATA);

#output results
$outRoot->set_pretty_print('indented');
$outRoot->print;#_to_file($Output_file_name);

sub motors{
  my ($twig, $elt)=@_;

  my $motor   = $elt->first_child('Instruction[@Type="Motor"]');
  my $motorID = $motor->att('ID');
  my $newRoot = $outRoot->insert_new_elt(
     'Motor'=>{ Name=> $motor->att('Name'),
                ID  => $motorID } ); 
  my %InOut=();
  for ( $elt->children( 'Input|Output' ) ){
    $InOut{'Motor_'.$_->gi}[ $_->att('ID') ] = $_->att('Text'); 
  }
  
  my $xpath='Wire[@ToID="'.$motorID.'" or @FromID="'.$motorID.'"]';
  for my $c ( $elt->children( $xpath ) ){
    my ($id,$text);
    if ( $c->att('ToID' ) eq $motorID ){
      $id   = $c->att( 'FromID' ); 
      $text = $c->att( 'ToText' );  
    } else {
      $id   = $c->att( 'ToID' ); 
      $text = $c->att( 'FromText' );  
    }    
    $newRoot->insert_new_elt('last_child', $text, $InOut{$text}[$id] )
  };
  
}
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