If too many MIDI messages are sent at once to the S2400 via USB, it seems to break the ability to receive midi messages.
Not sure if this will work universally but to reproduce on my machine:
- Connect the s2400 to a computer via USB
- Open this html file in any webMIDI compatible browser e.g. Microsoft Edge or Google Chrome
- Click the Zero All Faders button.
- The S2400 will not respond to midi in (restart to fix).
Hopefully the file makes sense. It is sending NRPN messages to zero the track level on each track. I did a bit of playing around and the s2400 seems to handle 3 or 4 NRPN messages before it fails.
I worked around the issue by adding a 20ms delay between each 9 byte NRPN message. With the delay everything seems to work fine so my guess is that the s2400 is overwhelmed when MIDI messages come in too fast.
On line 25 of the html file, changing the variable choke_s2400 to false to adds the 20ms delays.
EDIT - change the variable to false to add the delay.