Siemens S7-300 / S7-400 to S7-1500 Migration
Survey, I/O mapping, code conversion, panel retrofit, SCADA and HMI migration and a changeover planned around your shutdown window — executed by ATMAN Group engineers on running plants across process and manufacturing industries.
Discuss a Migration WhatsApp Our EngineersWhy Plants Migrate Off S7-300 and S7-400
The S7-300 and S7-400 families are out of current supply. Plants running them face four pressures at once: CPUs and I/O modules are available only from the grey and refurbished market, the engineering software sits on machines nobody can replace, the SCADA runs on an operating system IT wants off the network, and the person who wrote the programme has usually left. None of those stop production on the day — they decide how long an unplanned outage lasts when it happens.
Migration to the S7-1500 platform resolves all four together: current hardware with a supply line, TIA Portal engineering, a SCADA that is supportable, and documentation that belongs to the plant rather than to a person.
What Actually Changes
Two Ways to Do It
Like-for-like conversion. The existing logic is carried across with minimum change, so operators see the same machine behaviour on the first shift after start-up. Fastest, shortest shutdown, lowest training load. It also carries across whatever was wrong with the original programme.
Re-engineering. The control philosophy is rewritten against current standards — structured blocks, proper tag naming, optimised block access, alarms that mean something, and a SCADA built for the way the plant runs now rather than the way it ran in 2009. Longer and more expensive, and worth it where the plant has changed materially since the original commissioning.
Most projects are a mix: like-for-like on stable sections, re-engineering where the plant has outgrown the original design. We put the split in the scope in writing before the order, because it is the single biggest driver of the price.
Where Conversions Go Wrong
The migration tool moves the bulk of the blocks. What it does not resolve is where the time goes: legacy system function and library calls with no direct equivalent, absolute addressing that has to become symbolic, non-optimised block access retained for the wrong reasons, indirect addressing and pointer arithmetic, older communication and networking calls, cycle-time assumptions that change on faster hardware, and analogue scaling that quietly shifts. We budget for that work openly rather than discovering it during commissioning.
How We Run the Changeover
Site survey and documentation of what is actually installed, including a full I/O list taken from the panel rather than from old drawings. Hardware configuration and code conversion offline, with simulation and factory testing before anything reaches your site. Retrofit plates, marshalling and panel modification prepared in advance. Then the shutdown window: swap, loop checks, dry runs, start-up with our engineers on site, and stabilisation over the following shifts. Handover includes the programme sources, drawings, backups and operator training — the plant owns its own control system afterwards.
After the Migration
Annual maintenance, programme backup and version control, Siemens spares supply, and remote PLC and SCADA troubleshooting so that most faults are diagnosed before an engineer travels. We are a project, service and spare-parts provider; we are not an authorised Siemens channel.
Discuss a Migration
Tell us the CPU family, roughly how many I/O, the SCADA in use and the shutdown window you can offer, and we will come back with a method and an indicative budget.
Frequently Asked Questions
Can the existing S7-300 programme be converted automatically?
Partly. The TIA Portal migration tool converts the bulk of the blocks, but it does not resolve everything: legacy libraries and system function calls, absolute addressing, non-optimised block access, indirect addressing and older communication calls all need manual work. We treat the tool output as a starting point and then rewrite what will not hold, rather than handing over a converted programme nobody can maintain.
Do we have to replace the field wiring and the panel?
Not always. In many cases the existing MCC and field wiring stay and only the CPU, racks, power supply and I/O are replaced inside the panel, with a retrofit plate so the new modules fit the existing cut-outs. Where the panel is old, the wiring is brittle or the loading has changed, replacing the panel is the cheaper answer over the life of the plant. We decide that on site, not in the offer.
Can you migrate without stopping the plant?
A changeover needs a shutdown window, but it can be a short one. The programme is converted, tested offline and simulated in advance, marshalling and retrofit plates are prepared, and only the physical swap, loop checks and start-up happen during the shutdown. We plan the window against your production calendar and stage the work so a single line can be taken at a time where the plant allows it.
What happens to the SCADA and the HMIs?
The SCADA and HMI side migrates with the PLC. WinCC or WinCC Unified screens are rebuilt or upgraded against the new tag structure, legacy panels are replaced with current Comfort or Unified panels, and alarms, trends, recipes and reports are carried over — not left behind for a second project.
Is it worth migrating, or should we run the S7-300 until it fails?
That is a commercial question, not a technical one. The inputs are the spares position for your specific CPU and I/O, the cost of an unplanned outage on that line, whether anybody can still edit the programme, and whether the SCADA can stay on your network. We put those in writing so the decision is made on numbers rather than on fear of obsolescence.
Do you handle migration for makes other than Siemens?
Yes. We migrate from any make to Siemens, and within the same make, including Allen-Bradley, Mitsubishi and Delta systems. Siemens is our deepest expertise, but the survey, I/O mapping, code conversion and changeover method are the same discipline whichever platform you are leaving.