PLC programs and industrial software in an equipment sale
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A PLC program stored in a machine and a usable, transferable engineering project are not necessarily the same deliverable. Establish what exists, who controls it and what can be supplied before advertising software with an industrial asset.
The buyer may need information to maintain or reconfigure the equipment. The seller may also have customer data, shared licences and integrator-owned material in the same system.
Those interests need an agreed handover. They should not be settled by copying an entire engineering laptop onto a memory stick.
Identify the different items
Ask an authorised controls engineer to list the controller, operator interface, drives and relevant software. Record versions and project references where available.
Distinguish the program running in equipment from editable project files, backups, engineering software and licence evidence. Do not assume one file contains everything needed to restore or modify the system.
Siemens' September 2014 Automation License Manager manual provides a useful example of the distinction between a software licence, its certificate and the technical licence key. It also describes moving keys between storage locations. That older manual is not authority for transferring ownership in a current sale; check the actual product terms and supplier process.
The CNC software and backups guide applies the same questions to machine-tool controls.
Agree the handover in writing
Use these points to define the work with the seller, buyer and relevant integrator or supplier.
- Equipment covered: Name the asset references and control components included.
- Files available: List project names, versions and backup dates, with known gaps.
- Rights and permissions: Identify who will confirm whether each item can transfer.
- Access: Agree an authorised method for establishing buyer access without disclosing unrelated company credentials.
- Dependencies: Record required software, licences, hardware keys and external services.
- Technical verification: State who will check the handover files and what that check covers.
- Private information: Identify customer data and shared business information requiring a separate decision.
- Completion evidence: Record what was supplied, excluded or left unresolved.
A checklist does not replace a contract or specialist advice. It makes the unresolved decisions visible before the parties promise a complete controls package.
Check the backup against the installed machine
A backup date alone does not show whether it matches the current system. Ask the authorised engineer to compare the known change history and explain any uncertainty.
Do not describe a backup as tested unless the verification scope is recorded. Reading a folder successfully is different from establishing that it supports the intended restoration or engineering task.
For a palletising cell or robotic welding cell, the program may depend on tooling, safety arrangements and other integrated equipment. Keep the physical inventory and software record linked.
Changes to a live control system need the site's established technical process. Avoid resets, deletion or access bypasses undertaken merely to simplify the sale.
Decide what remains with the business
A shared engineering workstation may support retained machines. A network licence may serve several users. A supplier account may contain records for the whole factory.
Identify these relationships before allocating hardware to a lot. If the buyer receives the computer, that does not automatically mean they receive every account or right associated with it.
Equally, excluding a workstation can leave a material gap in the advertised package. Explain what the buyer will receive and which further supplier arrangements remain their responsibility.
Use the machinery document register to keep manuals, drawings and software schedules consistent.
Make unresolved access a visible limitation
If a supplier or integrator cannot confirm transfer rights or recover authorised access, state the unresolved position. It may affect the sale route, buyer assessment or timetable.
Contact UK Auction Group with the equipment inventory and controls handover schedule. Those records allow the sale discussion to reflect the available assets and permissions without promising unrestricted software access.
Return to the manufacturing and process equipment hub.
Sources
This guide gives general information. Equipment-specific, legal, tax and safety decisions may need a qualified adviser or competent specialist. The guides do not promise sale prices, fees or results.