NAME

Device::Modbus::RTU::Server - Perl server for Modbus RTU communications

SYNOPSIS

 #! /usr/bin/env perl
 
 use Device::Modbus::RTU::Server;
 use strict;
 use warnings;
 use v5.10;
 
 # This simple server can be tested with an Arduino with the
 # program 'arduino_client.ino' in the examples directory
 
 
 {
    package My::Unit;
    our @ISA = ('Device::Modbus::Unit');
 
    sub init_unit {
        my $unit = shift;
 
        #                Zone            addr qty   method
        #           -------------------  ---- ---  ---------
        $unit->get('holding_registers',    2,  1,  'get_addr_2');
    }
 
    sub get_addr_2 {
        my ($unit, $server, $req, $addr, $qty) = @_;
        say "Executed server routine for address 2, 1 register";
        return 6;
    }
 }
 
 
 my $server = Device::Modbus::RTU::Server->new(
    port      =>  '/dev/ttyACM0',
    baudrate  => 9600,
    parity    => 'none',
    log_level => 4
 );
 
 my $unit = My::Unit->new(id => 3);
 $server->add_server_unit($unit);
 
 $server->start;

DESCRIPTION

This module is part of Device::Modbus::RTU, a distribution which implements the Modbus RTU protocol on top of Device::Modbus.

Device::Modbus::RTU::Server inherits from Device::Modbus::Server, and adds the capability of communicating via the serial port. As such, Device::Modbus::RTU::Server implements the constructor and a logging method. Please see Device::Modbus::Server for most of the server-related documentation.

METHODS

new

This method opens the serial port to communicate using the Modbus RTU protocol. It takes the following arguments:

port

The serial port to open.

log_level

A number between 0 and 4, where 0 will log only emergencies and 4 will produce sufficient output for debugging. Default is 2.

baudrate

A valid baud rate. Defaults to 9600 bps.

databits

An integer from 5 to 8. Defaults to 8.

parity

Either 'even', 'odd' or 'none'. Defaults to 'none'.

stopbits

1 or 2. Defaults to 1.

timeout

Defaults to 10 (seconds).

disconnect

This method closes the serial port, but it is called automatically for you when the server is shut down with a SIG_INT.

log, log_level

This module will log messages to STDERR. The level of logging is set with the log_level argument to the constructor method. The logging level may be changed also with the method log_level.

log takes two arguments: The level of a message and the message itself:

 $server->log(3, 'This is the text to log');

SEE ALSO

Most of the functionality is described in Device::Modbus::Server.

Other distributions

These are other implementations of Modbus in Perl which may be well suited for your application: Protocol::Modbus, MBclient, mbserverd.

GITHUB REPOSITORY

You can find the repository of this distribution in GitHub.

AUTHOR

Julio Fraire, <julio.fraire@gmail.com>

COPYRIGHT AND LICENSE

Copyright (C) 2015 by Julio Fraire This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.14.2 or, at your option, any later version of Perl 5 you may have available.