MCT Nexus ENGINEERING RESOURCE
PLC Program Handover Checklist
Define the files, software versions, device configurations and operating information needed to maintain a PLC-controlled machine after delivery.
A running machine still needs a maintainable project package.
The program currently loaded in a controller is only part of the information needed to maintain an industrial machine. The handover may also require the native project, comments, HMI source, device configurations, libraries, software versions, drawings and the relationship between these files and the installed equipment.
Agree on these deliverables when the project scope is written. Waiting until commissioning is complete can expose missing files, unavailable licenses or uncertainty about ownership. MCT Nexus includes a defined handover discussion in PLC/HMI programming and controls engineering projects.
Identify the released software and its dependencies.
The final package should identify the PLC and HMI project files corresponding to the delivered machine revision. Record the development software versions and any relevant firmware or device configuration dependencies. A folder labeled “final” without version context is not a reliable release record.
Native project files are often necessary for future engineering changes. An upload from hardware may not recover every comment, source element, library or dependency from the original development project. Verify what the supplied files contain and whether the customer has the tools and licenses required to use them.
Reusable code and third-party software should have clear ownership and licensing terms. The handover should distinguish what the customer receives, what remains licensed and which supplier is responsible for support. These are contractual scope questions to resolve before delivery, not assumptions to leave to a maintenance technician.
Include configurations outside the PLC.
Controllers interact with drives, remote I/O, instruments, readers, network devices and other machines. Their parameters and configurations may be essential to reproduce the operating system. Identify which records are included and how they correspond to the installed devices.
The network documentation should show device identities, addresses, connection paths and interface ownership. Plant infrastructure may be administered by a different team; the machine package should identify the boundary rather than imply ownership of the entire plant network.
Access credentials must be handled through the customer’s approved secure process. They should not be placed in public documentation or sent through an ordinary website inquiry. The technical handover needs to establish who controls access and how authorized personnel obtain it.
Connect the software to the physical machine.
Electrical schematics, I/O lists and device identification help maintenance personnel interpret the software. The drawing revision should reflect approved changes made during installation and commissioning. A mismatch between a field label, drawing and tag description can make an otherwise well-structured program difficult to diagnose.
Include the operating narrative or sequence description where agreed. It should explain the intended machine states, modes, equipment interfaces and important recovery behavior. The HMI alone may not communicate all the assumptions behind the program.
If recipes or retained values are important, define what is backed up, what is provided as a default and what is expected to be maintained by the customer. A program file without the required operating data may not be sufficient to restore the intended production configuration.
Record what was tested and what remains open.
The handover should identify the software and hardware revision used during acceptance. Include the agreed test records and any remaining exceptions or operating limitations. This gives future support work a baseline for distinguishing an original limitation from a later change.
Changes made after FAT should be reviewed and recorded through the project’s change process. The final backup needs to correspond to the installed revision after those changes. A development copy stored before the last commissioning modification is not the final machine record.
For site acceptance, include the interfaces and production conditions that were verified. If a condition could not be tested, record the reason and the planned responsibility for completion. See the FAT planning guide for organizing this evidence.
Define backup and future-change responsibilities.
A useful handover states where the released files will be stored, who owns them and how later changes will be controlled. The customer should establish its own retention, access and recovery practices. MCT Nexus can supply the agreed project package without assuming ongoing administration of the customer’s systems.
Future changes should create an identifiable revision and a record of purpose, approval and verification. Preserve the appropriate baseline before modification. This practice supports troubleshooting and PLC migration when the equipment eventually needs further work.
Training can introduce the program organization, HMI diagnostics and file package to the appropriate audience. It does not replace required qualifications or authorization to work on the equipment. Use machine-specific examples and make escalation responsibilities clear.
Use a scope checklist before accepting the delivery.
- Native PLC and HMI project files for the installed revision.
- Development software versions and relevant firmware information.
- Device configurations and parameters included in the controls scope.
- Electrical schematics, I/O lists and network records.
- Required recipe or retained-data information and backup responsibilities.
- Third-party libraries, licensing and ownership boundaries.
- Sequence descriptions, alarm guidance and agreed recovery information.
- FAT/site acceptance records, open items and operating limitations.
- A clear location and responsible owner for the released package.
The exact package depends on the machine and the agreement. The goal is not to collect every possible document; it is to retain the information needed to understand, maintain and modify the installed system responsibly.
If an existing machine has incomplete records, start with an inventory rather than assuming every missing file can be recovered. MCT Nexus can define a documentation review that separates available records, verified information and gaps requiring further engineering work.
Discuss your project with MCT Nexus.
Share the equipment, production requirement and target timing. We will review the scope, interfaces and next steps with your team.