<?php require_once dirname(__FILE__) . '/../../Phpmodbus/ModbusMasterUdp.php'; require_once dirname(__FILE__) . '/../config.php'; // Create Modbus object $modbus = new ModbusMasterUdp($test_host_ip); // Data to be writen - INT $data = array(-12345); $dataTypes = array("INT"); // Write data - FC6 $modbus->writeSingleRegister(0, 12288, $data, $dataTypes); // Read data - FC3 $recData = $modbus->readMultipleRegisters(0, 12288, 1); print_r($recData);