On this HERA COP 160 t (6 m) press brake, the existing Pilz PSS 3000 safety controller was unreliable and occasionally caused downtime. A precise diagnosis was not possible because the software/project files were no longer available. In addition, the PSS 3000 is obsolete / out of service.
For these reasons, the operator decided to upgrade the safety control: PSS 3000 → PNOZmulti.
A customer-operated VPN connection was also implemented, allowing remote fault diagnosis and software adjustments to the safety control when required.
Scope (kept intentionally small)
For cost reasons, only the components that caused the problem were replaced:
- Safety controller: Pilz PSS 3000 → PNOZmulti
- Guard door position switches: tongue switches → Pilz PSENmag
- The remaining control system stayed in place
Procedure
- Electrical schematics were completely re-created, because the existing drawings were outdated due to age
- Safety software was developed for the PNOZmulti
- Hardware was replaced
- The control cabinet was adapted (installation, wiring, labeling, I/O mapping)
- Commissioning with systematic tests
- Troubleshooting until stable operation was achieved
Preparation and duration
As much work as possible was done in advance to reduce on-site risk and keep machine downtime low.
Even so, the on-site upgrade took 4 days, including commissioning and troubleshooting.
Remote access (customer VPN)
The VPN access is managed by the customer’s IT. It enables:
- Remote diagnosis (states, signal conditions, root cause analysis)
- Software changes within the agreed scope
- Faster response without travel
Documentation
- Electrical schematics (new)
- I/O list
- short functional description
- test/commissioning report
- archived project/version backup
Relation to the main retrofit article
This PNOZmulti upgrade was a separate step in addition to the retrofit described in the main article. The trigger was PSS 3000 downtime, missing software for diagnosis/changes, and the end-of-life status of the old controller.