Multi-Protocol PLC Discovery: How to Automatically Identify Devices on Your Factory Network [2026]
Commissioning a new IIoT gateway on a factory floor usually starts the same way: someone hands you an IP address, a spreadsheet of tag names, and the vague instruction "connect to the PLC." No documentation about which protocol the PLC speaks. No model number. Sometimes the IP address is wrong.
Manually probing devices is tedious and error-prone. Does this PLC speak EtherNet/IP or Modbus TCP? Is it a Micro800 or a CompactLogix? What registers hold the serial number? You can spend an entire day answering these questions for a single production cell.
Automated device discovery solves this by systematically probing known protocol endpoints, identifying the device type, extracting identification data (serial numbers, firmware versions), and determining the correct communication parameters — all without human intervention.
This guide covers the engineering details: protocol probe sequences, identification register maps, fallback logic, and the real-world edge cases that trip up naive implementations.