use Protocol::Modbus;

# Initialize protocol object
my $proto = Protocol::Modbus->new( driver=>'TCP' );

# Get a request object
my $req = $proto->request(
      function => Protocol::Modbus::FUNC_READ_COILS, # or 0x01
      address  => 4016, # Register dispavgVpv from MidNight Charger
      quantity => 1,
);

# Init transaction and execute it, obtaining a response
my $trn = Protocol::Modbus::Transaction->new( request=>$req );
my $res = $trn->execute();

# Pretty-print response on stdout
print $res . "\n";   # Modbus Response PDU(......)