EOL replacement finder

CM 1241 / CM 1242-5 (S7-1200 communication modules)

Your automation part went EOL — here is every way out, with the compatibility catch on each one.

Manufacturer: Siemens
Category: Communication module

Lifecycle status

No discontinuation notice exists for the classic CM 1241 / CM 1242-5 yet. The trigger is the S7-1200 G2 generation, which has its own communication modules; a G2 CPU does not take the classic ones. The forum thread on comms modules for the G2 runs past 20 replies before a cross-vendor answer lands.

Replacement paths, side by side

The decisive attribute in this vertical is software and runtime compatibility, not electrical specs. Read the compatibility column before the price column.

Route	What	Price band	Availability	Compatibility — the dealbreakers
Official successor	CM 1241 for S7-1200 G2 Siemens	Listed by EU distributors (Automation24, Kempston Controls); figure not yet recorded	Stocked by several EU distributors	Siemens' own RS232/422/485 module for the G2 generation (6ES7241-1EA50-0XB0). Same TIA Portal configuration approach, Freeport supported; a PROFIBUS module for G2 must be checked separately. Why this matters ⌄
Caveat: Only helps if the CPU is moving to G2 as well - it does not fit a classic S7-1200 rack.
Compatible third party	DP/PN coupler 700-158-3DP02 Helmholz	Helmholz publishes no list prices; its S7 components catalogue directs buyers to request a quote.	Distributor and direct	Protocol coupler rather than a slot-in module - it sits on the network instead of on the rack, so the hardware configuration changes even though the protocol behaviour is preserved. Why this matters ⌄
Caveat: Named at reply #21 of the thread, not reply #1 - this is not the obvious answer, which is exactly the gap these pages fill. discussed on SPS-Forum →
Used / refurbished	Used CM 1241 / CM 1242-5 Broker market	Not established in research	Broker and refurbisher stock	Identical hardware — the existing TIA Portal hardware configuration loads unchanged, with no GSD/GSDML work and no rewiring. Why this matters ⌄
Caveat: Buys time on an S7-1200 line without touching the project, but the G2 question returns at the next expansion.

Where the research did not establish a figure, this page says so rather than estimating one. A number you cannot defend is worse than no number.

What the community actually said

These pages are built from forum threads, not brochures. The tacit gotchas — the ones that are not on any datasheet — live in these discussions.

Comm modules for S7-1200 G2 · SPS-Forum.de

Links open a search on the forum the discussion took place on. German thread titles are given here in English translation.

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CM 1241 Ersatz
S7-1200 G2 Kommunikationsmodul
CM 1242-5 replacement
S7-1200 Profibus Modul Alternative