The $req variable gets the modbus reply.

#!/usr/bin/perl -l

use strict;
use warnings;
use Protocol::Modbus;

$|=1;

my $modbus = Protocol::Modbus->new(
    driver    => 'TCP',
    transport => 'TCP',
);

my $trs = Protocol::Modbus::Transport->new(
    driver  => 'TCP',
    address => '192.168.0.57',
    port    => 502,
    timeout => 3,
);

my $req = $modbus->request(
    function => 4,
    address  => 1,
    quantity => 75,
    value    => 0x0000,
);
print "=" x 60;
print "Response: ", $req;
print "=" x 60;
$trs->disconnect;

[download]

In reply to Re^3: Need help with Modbus by Khen1950fx
in thread Need help with Modbus by pashanoid

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.