S90XS

Is it possible to use both the “midi in” and the usb midi at the same time? I’d like to use the usb midi to communicate with my computer and the traditional “midi in” for my footcontroller at the same time.

Kind regards from Sweden

Yes.
Set your S90 XS so that MIDI IN/OUT = USB

This allows your S90 XS to communicate with your computer bi-directionally on five discreet MIDI ports simultaneously. Each “Port” represents a bi-directional communication bus with 16 channels.

Port 1 is for the MIDI data for the S90 XS itself. For your musical performance Notes, Controllers, Tempo.
Port 2 is to Remote Control your favorite supported DAW software
Port 3 is to connect an external MIDI device to your computer. Any device connected to the 5-pin MIDI IN jack will send its data through the S90 XS on to the computer. This data will not affect the S90 XS at all, but will arrive in your computer as “Yamaha S90 XS-3”. Any track in your DAW set to MIDI OUT = “Yamaha S90 XS-3” will again bypass the S90 and arrive at the 5-pin MIDI OUT jack (basically the S90 XS acts as a MIDI interface for that one external device.
Port 4 is reserved for the S90 XS/S70 XS EDITOR
Port 5 is for the REMOTE EDITOR (setting up control over VST soft synths you might run on your computer)

So you connect your foot pedal to the MIDI IN jack of th S90 XS.
You will need echo the signal from within a computer application so that data coming IN on Port 3, is re-routed back to the S90 XS via MIDI OUT on Port 1. For example, a MIDI Track in your DAW, etc.

Bad Mister!

Thank you for your fast and problem-solving reply, it should be easy to get this working with Cubase.

Kind regards from Sweden