Project Overview
The Challenge: Undocumented Legacy PLC on a Cable Production Line in Liverpool
A cable manufacturing facility in Birkenhead, Liverpool had recently acquired a second-hand Francis Shaw P255 cable extrusion line — but the machine was not running. The existing Siemens S5 PLC control system was operational, but no operating manuals, electrical schematics, or control system documentation came with the purchase.
The customer had created basic cabling and layout drawings, but the control logic was completely opaque. The PLC program contained no symbols, no comments, and no descriptions — making it impossible to understand the machine's intended operation, safety logic, or I/O architecture without significant reverse-engineering effort.
The only reference available was a hand-drawn cubicle circuit diagram from 1992 — over 30 years out of date and based on an earlier configuration of the same machine. With no specialist engineering support in place and a production deadline to meet, the customer needed expert intervention to get the line running safely and reliably.
Key challenge: no documentation, no spare parts history, no prior engineering support — and a production line that needed to run.
Our Solution: PLC Recovery, Drive Integration & Full Production Commissioning
Ashmit Engineering deployed an engineer to the Birkenhead site for a multi-day intensive engagement. Using our industrial control system expertise alongside our drives and motion control capability, the team executed a structured four-stage recovery:
On-site Interrogation & Reverse Engineering
Uploaded the Siemens S5 PLC program (no password protection was set) and systematically mapped all I/O points by cross-referencing installed hardware, operator panel labels, and the 1992 circuit diagram. Identified the machine's operating sequences — extruder start/stop, capstan speed control, wire-break detection, pre-length and length counter — entirely from observation.
Fault Identification & Safety Circuit Repair
During the first run test, the machine developed a system fault. Traced and resolved a wiring fault in the safety circuit and main power isolator — identified without any supporting documentation. This was the primary reason the machine had not been operable since installation.
PLC Program Rebuild from Ground Up
Rebuilt the Siemens S5 PLC program entirely from scratch using the intelligence gathered. The new program was fully documented with symbols, descriptions, and structured logic — leaving the customer with a maintainable, supportable control system for the first time in the machine's history at this site.
Parker Drive Integration & Production Validation
Integrated independent speed control for the extruder and capstan drives using Parker SSD and the new Parker 6901-00-G speed controller. Configured drive parameters, speed feedback (tacho calibration), and Estop communication. Validated the complete system against production run requirements before sign-off.
Throughout the project, Ashmit Engineering maintained open communication with the customer on parts requirements, progress, and the planned approach — in line with our support and consultancy methodology.
Results Achieved
Production Line Restored
Full production run validated after 4 days on-site. The cable extrusion line was operational for the first time since the customer's acquisition.
System Fully Documented
PLC program rebuilt with complete symbol table, structured logic, and descriptions — leaving a maintainable, supportable system.
Safety Circuit Certified
Wiring fault in the safety circuit and main power isolator identified and resolved. Machine operates safely within its intended interlocking design.
Drive Synchronisation Commissioned
Independent extruder and capstan speed control commissioned via Parker drives — matched to production speed requirements.
IEC 62443 Aware Design
Control system redesigned with industrial cybersecurity best practices, including documented access controls and structured program architecture.
12-Month Warranty
Full 12-month warranty provided on all work delivered — giving the customer confidence in long-term production reliability.
The customer now has a fully operational cable extrusion line with a documented, maintainable control system for the first time since the machine entered the factory. The engagement transformed an inoperable second-hand asset into a production-ready line — with engineering documentation that will support the machine for years ahead.
Project Photos
Automation & Control Services Available in Liverpool & Merseyside
Available for site visits throughout Liverpool, Birkenhead, and Merseyside — typically within 48 hours. We work directly with factory managers, production directors, plant engineers, and procurement teams.
Frequently Asked Questions
- Do you work in Liverpool and Merseyside?
- Yes. Ashmit Engineering engineers work across Liverpool, Birkenhead, and the wider Merseyside area. We can typically be on-site within 48 hours of your enquiry — and same-day for genuine production emergencies.
- Can you recover a PLC system with no documentation?
- Yes — this is a core speciality. Our engineers reverse-engineer undocumented PLC programs by interrogating the controller directly, reading installed hardware, reviewing operator panels, and observing machine behaviour in production. We rebuilt the entire PLC program for this Liverpool cable factory from scratch without a single manual or schematic.
- What PLC brands do you support?
- We work across all major PLC brands including Siemens S5 and S7, Allen-Bradley (Rockwell), Mitsubishi, Omron, Schneider Modicon, and Beckhoff. We also support SSD, Parker, ABB, and Siemens drives.
- Can you support obsolete control systems where spare parts are no longer available?
- Yes. Obsolete and end-of-life control systems are a common challenge. Our team identifies compatible modern replacements, reverse-engineers the existing logic, and migrates functionality to supportable hardware — minimising production disruption.
- What does IEC 62443 mean for industrial control systems?
- IEC 62443 is the international standard for industrial cybersecurity. It defines security levels for control systems to protect against unauthorised access, data tampering, and operational disruption. We incorporate IEC 62443-aware design practices into our PLC and automation projects, particularly for networked or remotely accessible control systems.
- How quickly can you respond to a production breakdown in Liverpool?
- Our 24/7 emergency line is available around the clock. For production-critical faults in Liverpool and Merseyside, we aim to have an engineer on-site same day or next morning. Call +44 20 3129 5414 immediately if your line is down.
- Do you offer ongoing support after commissioning?
- Yes. All work delivered by Ashmit Engineering carries a 12-month warranty. We also offer ongoing support contracts, remote monitoring arrangements, and preventive maintenance programmes tailored to your production schedule.
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Get a Quote for PLC Automation in Liverpool or Merseyside
Our engineers have delivered industrial automation and control system upgrades throughout Liverpool, Birkenhead, and the wider Merseyside region. We can typically be on-site within 48 hours of your enquiry.