Hello Chris.
Both decoders are for turnouts, 74461 is for normal turnout and 74465 is for threeway turnout.

This is 74461:
Built-in digital decoder

Installed in all C Track turnouts with electric drive. Connection via plug contacts. Address 1 to 256. adjustable with coding. For the electric turnout can be used simultaneously or subsequently a digital decoder. The decoder is easily connected with plug contacts and can be addressed individually for each switch (address 1 to 256). Tools or special skills are required for installation. The digital power supply can be taken directly from the track current contacts on the turnout. In this way, a complete digital turnout that is ready for immediate use on mobile equipment.

and this 74465:
This decoder can be installed in the C Track three-way turnout (24630) with electric mechanisms. It can be used with the digital formats Motorola and DCC. Connections are made with plug-in contacts, for Märklin and Trix C Track turnouts. An address can be set with coding switches (Motorola Format 1 to 320 / DCC Format 1 to 511), and can also be set on the programming track. Turnout lanterns can be connected and can be controlled (soldering skills required). A digital decoder can be installed at the same time as the electric turnout mechanism or can be installed later. The decoder is easily connected with plug-in contacts and can have a custom address set for each turnout. The digital power supply for the decoder can be taken directly from the track current contacts on the turnout. This means you can have a complete digital turnout that can also be used on temporary layouts.

Regards

Jukka

Jukka

Your description appears to be for the 74460 not 74461

While both 74460 and 74461 are for single motor turnouts ...

the 74460 is old school (MM only, DIP swicth addressing only)
ref medienpdb.maerklin.de/product_files/1/pdf/74460_betrieb.pdf

the 74461 and 74465(3 Way variant) are the same generation (MM/DCC, DIP or program addressing)
ref medienpdb.maerklin.de/product_files/1/pdf/74461_betrieb.pdf
ref medienpdb.maerklin.de/product_files/1/pdf/74465_betrieb.pdf

Note: the MM 256 address limitation is a 6021 control unit one, not a device one, The devices in MM mode can address to 320.