Siemens SIMATIC S7-300, ET 200M - these assemblies will enter the phase-out period as of 01 October 2025

On 01 October 2025, a chapter in automation technology will come to an end: 268 assemblies of the SIMATIC S7-300 and ET200M will enter the phase-out period. For many companies, this marks a critical turning point - as the S7-300 has been the workhorse in machines, systems and automated infrastructures worldwide for many years. 

To save you from wading through endless lists, we have examined the phase-out announcement for you, structured it and grouped it into clusters. This provides you with a quick overview of where your systems are affected. If the cluster view is not sufficient, you will find the complete list of all assemblies concerned further down in the article. 

The phase-out affects a total of 268 SIMATIC S7-300 and ET 200M assemblies. That can easily become confusing. We have reviewed the affected assemblies and created a clear cluster with six categories. 

1. S7-300 CPUs – the core of the control system 

From the compact CPU312 and 313, through the flexible CPU314/315, to the powerful CPU317 and 319: the fail-safe F variants as well as the technology CPUs(T) are also affected. 

2. S7-300 input/ output assemblies – the largest group

This is where most of the phase-outs are found:

• Digital I/O: SM321, SM322, SM323 – from standard to relay assemblies
• Analogue I/O: SM331, SM332, SM334, SM336, SM338 – including HART and Ex variants
• Fail-safe assemblies: SM326 series

3. S7-300 communication & networks 

The interfaces to the outside world are also facing phase-out:

• Serial CP340/341
• Profibus CP342-5
• Industrial Ethernet CP343-1 (Lean, Standard, Advanced)
• Telecontrol modules (TIM / SINAUT)

4. S7-300 function and counter modules

Counters, positioning and special modules such as the FM350, FM351, FM352 or the SIWAREX weighing electronics are also affected

5. Infrastructure & accessories

Oft übersehen, aber entscheidend im Alltag:

• Interface modules (IM153, IM360/361/365)
• DIN rails, bus modules, simulation and dummy modules
• Front connectors, cables, labelling sets

6. Memory & power

• MMC memory card from 64 KB to 8 MB
• Batteries and supercaps for real-time buffering

With our clustering, you gain clear orientation:

• Quickly check which areas of your systems are affected
• Set priorities: start with core assemblies (CPU, I/O), then move on to infrastructure and accessories
• Plan your Supply Strategy - secure spare parts, schedule maintenance and repairs, or consider migration options

The phase-out is not only a challenge, but also an opportunity: those who act proactively now can prepare their automation for the decades to come. 

If you have any questions or require detailed advice, please contact us, we are here to help!