A Raspberry PLC deployed in a field, a solar microgrid or a wastewater lift station is often hours from the nearest engineer. Reaching it does not require proprietary software or a custom integration, it requires a cellular gateway that can forward a port, which is exactly what one of our distributors, Valtoris, documented in a public integration guide.
Why does remote access matter for a PLC in an off-grid site?
System integrators increasingly deploy Industrial Shields PLCs as part of IIoT installations with no fiber or broadband nearby: smart irrigation systems, solar microgrids, wastewater lift stations. When a logic error needs fixing or the code needs an update, driving out to plug into the PLC's Ethernet port in person is slow and expensive, and sometimes not even possible on short notice.
The fix is not a special piece of Industrial Shields hardware. It is a cellular gateway providing backhaul on site, and a Raspberry PLC that is already built to be reached over a standard network.
A Raspberry PLC speaks standard Linux, not a proprietary protocol
The Raspberry PLC family is, in practice, a Linux-based edge device, with SSH already available out of the box over its Ethernet port. That single fact is what makes remote access possible without any Industrial Shields-specific driver, agent or cloud service in the middle. Any device capable of routing traffic and forwarding a port to a LAN address can reach it, cellular gateway or otherwise.
The pattern one of our distributors already documented
Valtoris, one of our distributors, published a public integration guide showing exactly this: a Raspberry PLC connected over Ethernet to a Valtoris 4G LTE industrial gateway, with the gateway forwarding a custom external port to the PLC's SSH port. Once configured, an engineer can SSH into the PLC's terminal from anywhere with a signal, no site visit required for a software fix or a diagnostic session.
The full configuration steps, including the exact port forwarding fields and screenshots, are in their guide. We are not repeating them here, they already covered that well, and the steps are specific to their gateway's interface.
This works with any gateway that does port forwarding, not only one brand
The requirement is not a Valtoris gateway specifically. It is a gateway capable of NAT and port forwarding to a LAN device, a completely standard feature across industrial cellular routers and M2M gateways. If your team already trusts a different vendor for cellular backhaul, the same pattern applies: forward an external port to the PLC's SSH port, and you have remote access. This is what an open ecosystem is supposed to do, let the tools you already trust connect to the hardware without asking Industrial Shields to build or certify anything specific for them.
It is also a useful example of what a distributor relationship can produce beyond reselling hardware: a real, field-tested integration guide for a problem Industrial Shields itself does not sell a product for.
Before you expose SSH to the public internet
Port forwarding a custom external port to SSH, as shown in the guide, is a reasonable starting point, and using a non-standard port does cut down on basic automated scans. It is a minimum, not a ceiling, for a production deployment.
For anything beyond a handful of sites, consider disabling password authentication in favor of SSH key pairs, keeping the OS on the PLC patched, and evaluating a VPN tunnel back to the gateway instead of a direct port forward once the number of exposed PLCs grows. None of this changes the underlying pattern, it just hardens it as a basic industrial cybersecurity practice, not an optional one.
Read the full configuration guide
The complete port forwarding configuration, with the exact fields and screenshots for a Valtoris gateway, is in their integration guide: How to Enable Remote SSH Access for Industrial Shields RPi PLCs.
If you are evaluating hardware for a similar off-grid deployment, the Raspberry PLC range is the starting point on our side.