Category Archives: PLC Communication

A practical engineering guide to configure Modbus TCP on the Mitsubishi MELSEC iQ-R series — quick setup, GX Works3 parameters, MODBUS Device Assignment, function codes, exception codes, float/endian handling, polling timing, and field troubleshooting Quick Setup (5 Steps) If you just need it working fast, here’s the short path: Step Action 1 GX Works3 → Module Parameter →… Read More: Modbus TCP Mitsubishi iQ-R: Step-by-Step Setup (GX Works3, RJ71EN71, RnENCPU) »

The Schneider Modicon M340 PLC is one of the most widely deployed PLCs in Europe, the Middle East, and Africa for water treatment, building automation, energy management, and machine control. Modbus TCP is its default Ethernet protocol — the embedded CPU Ethernet port is a Modbus TCP server out of the box. This guide shows you how to… Read More: How to Configure Modbus TCP on Schneider M340 (Unity Pro… »

PROFINET is the default communication protocol on every Siemens S7-1200 and S7-1500 PLC. The PROFINET interface is built into the CPU — no extra modules needed. But setting up a PROFINET network in TIA Portal involves several steps that must happen in the right order. You need to install the GSD file, add the IO-Device to the network,… Read More: How to Configure PROFINET in TIA Portal (Step-by-Step Guide) »

Allen-Bradley CompactLogix and ControlLogix PLCs do not support Modbus TCP natively. Their primary protocol is EtherNet/IP. But in many industrial systems, you need to communicate with Modbus TCP devices — energy meters, VFDs, third-party sensors, or legacy equipment. Rockwell Automation provides a free solution: Modbus TCP Add-On Instructions (AOIs). These are pre-built function blocks you import into Studio… Read More: How to Configure Modbus TCP on Allen-Bradley CompactLogix (Studio 5000… »

The Siemens S7-1200 has built-in Modbus TCP support. No additional communication modules are needed. The CPU handles Modbus TCP natively through its PROFINET Ethernet port. You configure it using two instruction blocks in TIA Portal: A single S7-1200 can run both roles at the same time — serving data to SCADA while polling field devices. Despite the simplicity,… Read More: How to Configure Modbus TCP on Siemens S7-1200 (TIA Portal… »

You’ve got a PLC on the factory floor. You need its data in your SCADA, MES, historian, or cloud platform. OPC UA is the way to get it there — securely and without vendor lock-in. But the steps depend on what PLC you have. Some PLCs have OPC UA servers built right in. Others need external software or… Read More: How to Connect a PLC to OPC UA: Setup Guide… »