Oh I didn’t know I can split the cables ! Thank you.

MADI cabling is possible with multimode and single mode.

Multimode supports up to 2 km cable length between each of the devices (regardless of OM3 or OM4), even if you daisy-chain multiple devices.
Single mode is laser-based and supports even 10 km between each of the devices.
So, for most setups, multimode is the way to go and more than enough in terms of supported cable length.

RME devices without SFP slot are from the factory equipped with multimode transceivers. Single mode is possible, but only on special order. But this is not the case here; otherwise you would have told this.

As you cannot mix single and multimode you need to deploy with multimode cables!
Because of this, you need a multimode SFP for devices with SFP slot (e.g., the M-32 Pro II).

I recommend you to get the multimode SFP from RME, if you pick the wrong one (which can happen easily) then nothing will work at all. Background: there are different types of SFPs on the market with different firmware for network devices of different vendors. Furthermore, different wavelengths are supported.

For multimode cable, you can use OM3 or OM4.
Best is to stick to one cable standard between two devices, or even better for the whole setup.

If you have an in-house cabling, connecting different rooms with different patch panels, then you definitively need to stick to either OM3 or OM4. Mixing the cable standards between two MADI devices leads to higher dampening and can cause issues of its own.

If you have "green field", then I would choose OM4.
But also OM3 will do well and not change the maximum cable length for an RME setup.

If you should ask yourself which type of multimode cable you have there …
They have standard colors, you can google for it. OM3 has aquamarine, OM4 has violet.

The next thing is that you have to look for the proper multimode fiber connector as your devices use different standards.

The UFX+ uses SC connectors. If you have a device with transceiver (M-32 Pro II) then you need an LC connector.

UFX+---SC------LC---M32ProIIAD---LC------LC---M32ProIIDA---LC------SC---UFX+

So in your setup you need:
2x SC-LC → LWL Patch cable Duplex SC/LC 50/125µ OM4
1x LC-LC → LWL Patch cable Duplex LC/LC 50/125µ OM4

Usually, you get duplex cables in the shops easier.
With the LC-LC duplex cable, you can leave the unused fiber free (then you have a backup wire). Or you need to split the duplex cable carefully. Or, you need to remove carefully the removable plastic bridge (clip) that holds both connectors together to split a duplex cable.

Regarding cable length. When choosing the patch cable, I would simply use the appropriate length, in a rack either 0.5, 1, 2 or 3m. When deploying, be sure to observe the following: Fiber cable must not be kinked (makes cable unusable) and the cables should not be bent too much (can lead to higher dampening or even damage the cable). Therefore, note the maximum possible bending radii. You can use the way the cable was delivered from the factory in the plastic bag as a guide.

You can also take a look at the pictures and drawings in my blog. I also have to use patch cables with SC and LC connectors for connecting UFX+ / UFX III, 12Mic, Octamic XTC:

From current setup (stereo setup with two amps and Lexicon PCM 81, 91)

https://www.tonstudio-forum.de/blog/ent … iii-en-de/

Back:

Front:

Here is the cabling diagram of the previous setup (mono setup for the amp), here in the diagram you can see how the devices are daisy-chained.

https://www.tonstudio-forum.de/blog/Ent … -DURec-DE/

The complete setup with Recording and HIFI corner. The PC acts also as a Music player using MusicBee, which can nicely be remotely controlled by the Android app MusicBee remote.
In the HIFI corner I am using a TOSLINK switch from Oehlbach, Optosel 4:1 Mk II (note: only the MK II version supports up to 192 kHz). There I can switch between up to four optical sources using a remote or at the Optosel.
Currently 3: UFX III, TV, BluRay Player

“ If you should ask yourself which type of multimode cable you have there …
They have standard colors, you can google for it. OM3 has aquamarine, OM4 has violet.”

The RME SFP Modules came each with an orange cable.

I split both and use one side each:

1 from UFX+ Output to M32 AD input
1 from M32 DA output to UFX+ Input

Leaves me with a redundancy for both cables which I can’t use for the connection between both M32 due to different connector on one side.

Now I need to buy a cable from M32 AD output to M32 DA Input.

Should I buy OM3 or 4?