A very trivial example

Here is a script that implements a virtual motor. Does does nothing else but else but changing a global symbol.

Before the virtual motor can be used, the following command has to be entered: ONLINE> def vm1.

#!/usr/bin/perl -w
#
# file name: /online_dir/vm1.pl
#
# This script is a template for a virtual motor. 
# 
my ($method, $value_new) = @ARGV; 

$Spectra::dummy_vm1 = 0 if( !defined( $Spectra::dummy_vm1)); 

my $status = 1; 

if( $method eq "set_position")
{
    $Spectra::dummy_vm1 = $value_new; 
}
elsif( $method eq "get_position")
{
    $SYM{RETURN_VALUE} = $Spectra::dummy_vm1;
}
elsif( $method eq "get_limit_min")
{
    $SYM{RETURN_VALUE} = -100;
}
elsif( $method eq "get_limit_max")
{
    $SYM{RETURN_VALUE} = 100;
}
elsif( $method eq "exec_stop")
{
    Util::log( "method exec-stop"); 
}
else
{
    Spectra::error( "vm1: failed to identify $method"); 
    $status = 0;
    goto finish;
}
finish:
 $status;