MES Integration Series · Part 3
MES Integration Reliability and Cybersecurity
What keeps the data safe when the network fails or someone attacks?
Machine data must reach the MES even when a cable is cut, and it must not give an attacker a way into the machines. Reliability comes from buffering, acknowledgements and retries. Security comes from encryption, certificates, access rules and separated network zones. Try the outage and retry tools below. The values are examples.
While the link is down the gateway keeps messages in its local storage. When the link returns it sends the backlog and the new data together, so the link must be faster than the live rate. If the buffer fills, the oldest data is lost.
After a failure the sender waits, then doubles the wait each time up to a limit. A little random jitter stops hundreds of machines retrying at the same instant.
| Failure | What the plant sees | Defence |
|---|
Pick a failure to see what protects the data.
The safest design lets the machine side connect outwards to a middle zone, and never lets the business network connect straight into the machines. Change the setting to see the paths.
| Stage | Tools shown in the case | What they do here |
|---|
The tools are examples, not recommendations. Choose by what your team owns and what your machines and PLCs support.
The simulations are simplified teaching models. Security design must follow your own risk assessment, your IT team and the relevant standards.