Why Remote Access Has Become Essential
Sending a technician on-site to restart a PLC, adjust a setting, or read a fault is costly in terms of time, travel, and production downtime. IoT remote access eliminates the need for on-site visits in most cases: issues can be diagnosed, corrected, and the system can be brought back online right from the office.
The benefits are immediate:
- Response time reduced from several hours to just a few minutes;
- Travel costs significantly reduced;
- Improved availability of lines;
- Support available at remote locations or on-site at customer locations.
See also the Industrial Remote Maintenance page and the Reducing Field Trips guide.
The Trap: Insecure Remote Access
The problem isn’t remote access itself, but the way it’s often cobbled together: RDP exposed to the Internet, VNC left open, a manufacturer-provided 4G modem per machine, passwords shared among service providers, and permanent access that’s never disabled. These practices are the primary entry point for ransomware in the industry.
A true IoT remote access solution adheres to five principles:
- Outbound tunnel — the connection originates from the gateway; no ports are exposed.
- Strong authentication (MFA) and named accounts.
- Least privilege — access limited to only the equipment strictly necessary.
- Time-bound sessions that can be revoked instantly.
- Comprehensive logging for auditing and compliance NIS2.
Architecture of a Secure Remote Access System
The technician works with their usual tools (TIA Portal, Control Expert, Studio 5000, etc.) but can only view authorized resources. Details by PLC brand are covered in Remote PLC Access.
IoT Remote Access vs. Consumer Remote Desktop
| Criterion | AnyDesk / TeamViewer | IoT Remote Access |
|---|---|---|
| Target | A PC | OT equipment (PLCs, HMIs, sensors) |
| Exposure | Depends on configuration | Outbound tunnel, nothing exposed |
| Permissions | Global | By site / device / role |
| Duration | Permanent | Limited, revocable |
| Audit | Limited | Full logging |
| Remote locations | Depends on the PC | Standalone 4G/5G gateway |
The Eziwan Approach
Eziwan Industrial Remote Access replaces scattered access points with a single gateway, managed from the Eziwan Cloud. Outbound VPN tunnel, MFA, role-based permissions, time-stamped logs, and connection notifications: you can grant access to your technicians and service providers without ever exposing the OT network.
It all works even without a landline, thanks to 4G/5G connectivity and the built-in IoT SIM card. To understand the encryption module, continue with IoT VPN.