Hi Allan,
the S970 has NO so called "MFC10 tab" in MIDI setup. This means, a MIDI foot pedal (like Yamaha MFC10) can NOT be used in the "normal" way (as usual with Tyros models) to switch certain functions by sending NOTE events.
You can use SysEx and Control Change (CC) commands, of course, to control the S970 by an external MIDI (foot) controller. But these commands must be programmed/stored in the external controller. On S970, you have only the "Receive" tab in MIDI setup, but NO MFC10 tab, so you can NOT set a certain MIDI channel to use incoming NOTE commands for controlling "switch functions" of the S970.
Best regards,
Chris