Connect the factory without flattening IT and OT

The challenge on the ground

Connecting machinery to reporting systems often creates an accidental bridge between the corporate network and equipment never designed for unrestricted access. Engineers need visibility, but a cloud outage or an office incident should not become a dependency for local machine control.

Start with the actual controller protocols and operating constraints.

Inside the design

Use managed Catalyst switching for the plant distribution layer, with dedicated access segments for each cell. Place an appropriately sized industrial firewall and an integration zone between OT and corporate services. These security appliances are project-specific additions to the hardware BOM.

Only named flows cross that boundary: for example, a historian collector may read a controller while general office clients cannot. Use RUT956 cellular access for a separately protected maintenance path, not an unfiltered back door into PLC networks.

Operating it day to day

Route supplier access through an approved jump host with individual identities, MFA and an expiry window. Log the session and remove access at the end of the work order.

Keep machine safety and real-time control local. Back up controller and switch configurations before maintenance, and agree the rollback decision with production rather than treating firmware updates as ordinary office patching.

What to test before handover

1. Demonstrate that an office client cannot initiate a session into a production cell.
2. Verify each historian flow against the approved protocol and destination list.
3. Disable the WAN and confirm local production control remains available.
4. Exercise supplier access, expiry and the maintenance rollback procedure.

Technical references

• Manufacturer technical documentation