Passwordless Access Control for Industrial Machines
A secure SMS-based challenge/response system that lets your PLC verify operator identity — without usernames, passwords, or a network connection at the machine. Just a button press and a text message.
Five steps. No passwords. No network at the machine. Just a text message and a verified identity.
The operator presses an access button on the HMI. The PLC instantly generates a unique random 6-digit challenge code and displays it on screen.
The operator texts that 6-digit code to the phone number associated with their manufacturing plant — no app required, just a standard SMS.
The Icon Access web service receives the text, looks up the operator's phone number, and verifies their identity and access level in real time.
Based on the operator's credentials and the challenge code, the web service calculates and texts back a unique 6-digit response code.
The operator enters the response code on the HMI. The PLC independently runs the same algorithm to validate the code — no network connection required at the machine.
Eliminate shared passwords, forgotten credentials, and unauthorized sharing. Access is tied to a verified phone number — something the operator already has.
The PLC validates the response code independently using its own algorithm. The machine never needs to connect to the internet or your plant network.
The algorithm can be implemented on any PLC platform — No special hardware required.
Different operators get different access levels. A maintenance tech can adjust parameters an operator cannot. All controlled from a simple web portal.
Every access request is logged — who requested access, when, and from which machine. Complete traceability for compliance and incident review.
A dedicated iPhone and Android app will make the process even faster — scan a QR code on the HMI and receive your access code instantly.
Restrict who can modify machine recipes, setpoints, and production parameters.
Allow access to maintenance screens, manual modes, and site-approved service procedures.
Require authentication before operators can change tooling offsets or setup parameters.
Ensure only authorized quality personnel can release a machine from a quality hold.
Require approved authorization for restricted production decisions, protected functions, or exception handling — with a full audit trail.
Getting started with Icon Access doesn't require you to build the algorithm from scratch. We distribute the PLC logic needed to implement the challenge/response validation directly in your controller — so you can be up and running quickly on any supported platform.
Whether you're an OEM building machines, a system integrator deploying automation cells, or a plant looking to retrofit existing equipment — the logic is ready to drop into your project.
Provided as a self-contained function block or routine. Minimal integration effort — just call it from your existing program.
The PLC validates the response code independently. No internet connection required at the machine during normal operation.
Compatible with major PLC platforms including Allen Bradley, Siemens, Omron, and more. Contact us for your specific platform.
Register your interest to be notified when Icon Access launches and to get early access information.
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