{"id":8052,"date":"2026-07-14T09:00:00","date_gmt":"2026-07-14T07:00:00","guid":{"rendered":"https:\/\/www.i-t-s.be\/?p=8052"},"modified":"2026-11-13T13:11:59","modified_gmt":"2026-11-13T12:11:59","slug":"plc-migration-end-of-life-5-steps","status":"publish","type":"post","link":"https:\/\/www.i-t-s.be\/index.php\/2026\/07\/14\/plc-migration-end-of-life-5-steps\/?lang=en","title":{"rendered":"Replacing an end-of-life PLC: the 5 steps of a successful migration"},"content":{"rendered":"\r\n

Technical corner \u00b7 Automation \u00b7 6 min read<\/strong><\/p>\r\n\r\n\r\n\r\n

Spare parts no longer available, software that only runs on an old PC, nobody who really knows the program: many plants live with end-of-life PLCs. As long as the machine runs, the decision is postponed. Until the day a card fails and the stop lasts days instead of hours.<\/p>\r\n\r\n\r\n\r\n

Replacing a PLC is not just a hardware swap. Well prepared, it is also an opportunity to make the machine more reliable and easier to troubleshoot. Here are the 5 steps of a successful migration.<\/p>\r\n\r\n\r\n\r\nPLC migration: the 5 steps<\/text>1<\/text>Initial survey<\/text>existing program, diagrams, I\/O, links with other machines<\/text>2<\/text>Functional analysis<\/text>describe what the machine must do, with production and maintenance<\/text>3<\/text>Hardware choice and preparation<\/text>PLC, HMI, I\/O, updated electrical diagram, office testing<\/text>4<\/text>Planned changeover<\/text>short stop, pre-wired panel, communication with neighbouring machines<\/text>5<\/text>Commissioning and documentation<\/text>tests, tuning, training, status manual, as-built diagrams<\/text><\/svg>\r\n\r\n\r\n\r\n

1. Survey the existing installation<\/h2>\r\n\r\n\r\n\r\n

Gather everything that exists: program backup, electrical diagrams (often out of date), list of inputs and outputs, links with neighbouring machines. This is also the time to note known problems and the teams’ requests.<\/p>\r\n\r\n\r\n\r\n

2. Write the functional analysis<\/h2>\r\n\r\n\r\n\r\n

This is the most often neglected step, and the most profitable. It describes what the machine must do: sequences, operating modes, safety functions, faults. Validated with production and maintenance, it becomes the reference for programming and testing.<\/p>\r\n\r\n\r\n\r\n

3. Choose the hardware and prepare<\/h2>\r\n\r\n\r\n\r\n

The choice depends on the size of the machine and the existing installed base: for example a Siemens S7-1200 G2 for a compact machine, an S7-1500 for a more complex line. The new electrical diagram and the operator panel are prepared, and the program is tested in the office, in simulation, before going on site.<\/p>\r\n\r\n\r\n\r\nConvert the old program or rewrite it?<\/text>Criterion<\/text>Conversion<\/text>Rewrite<\/text>Engineering time<\/text>shorter<\/text>longer<\/text>Original flaws<\/text>kept<\/text>fixed<\/text>Readability<\/text>old structure<\/text>clear, documented<\/text>Diagnosis<\/text>unchanged<\/text>statuses and faults on screen<\/text>Suited if\u2026<\/text>same brand, clean code<\/text>other brand, poorly known code<\/text><\/svg>\r\n\r\n\r\n\r\n

Automatically converting the old program looks faster. But it keeps the original flaws and a structure that is hard to read. Starting again from the functional analysis gives a clear, documented program with a real diagnostic screen.<\/p>\r\n\r\n\r\n\r\n

4. Plan the changeover<\/h2>\r\n\r\n\r\n\r\n

Everything that can be prepared in advance should be: cabinet or panel pre-wired, terminals labelled, communication with neighbouring machines tested. The on-site changeover then becomes a short, controlled stop rather than an adventure.<\/p>\r\n\r\n\r\n\r\n

5. Commission and document<\/h2>\r\n\r\n\r\n\r\n

Function-by-function tests, tuning, training of operators and technicians, then handover of up-to-date documentation: diagrams, status manual, program backup. This is what will allow fast troubleshooting in the years that follow.<\/p>\r\n\r\n\r\n\r\n

A real example<\/h2>\r\n\r\n\r\n\r\n

On the Biko unwinder at Elis Belgium<\/a>, ITS replaced the B&R PLC with a Siemens S7-1200 G2, rewrote the program from a functional analysis, installed a new diagnostic panel and delivered complete EPLAN electrical diagrams. Commissioning: 3 days.<\/p>\r\n\r\n\r\n\r\n

To go further on diagnosis, read also: Machine breakdowns: cut diagnostic time<\/a>.<\/p>\r\n\r\n\r\n\r\n

An end-of-life PLC on one of your machines?<\/strong> Let’s talk<\/a> before it breaks down.<\/p>\r\n\r\n\r\n","protected":false},"excerpt":{"rendered":"

Unavailable spare parts, poorly known program: replacing an end-of-life PLC needs preparation. Survey, functional analysis, hardware choice, planned changeover, documentation: the 5 steps of a successful migration.<\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_hide_featured_image":false,"_jetpack_featured_image_duplicate_dismissed":0,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[126],"tags":[],"class_list":["post-8052","post","type-post","status-publish","format-standard","hentry","category-technical-corner"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/www.i-t-s.be\/index.php\/wp-json\/wp\/v2\/posts\/8052","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.i-t-s.be\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.i-t-s.be\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.i-t-s.be\/index.php\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.i-t-s.be\/index.php\/wp-json\/wp\/v2\/comments?post=8052"}],"version-history":[{"count":1,"href":"https:\/\/www.i-t-s.be\/index.php\/wp-json\/wp\/v2\/posts\/8052\/revisions"}],"predecessor-version":[{"id":8053,"href":"https:\/\/www.i-t-s.be\/index.php\/wp-json\/wp\/v2\/posts\/8052\/revisions\/8053"}],"wp:attachment":[{"href":"https:\/\/www.i-t-s.be\/index.php\/wp-json\/wp\/v2\/media?parent=8052"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.i-t-s.be\/index.php\/wp-json\/wp\/v2\/categories?post=8052"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.i-t-s.be\/index.php\/wp-json\/wp\/v2\/tags?post=8052"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}