When using any of the factory X-Station templates, or when using the X-Station in synth mode, the sustain pedal input will be assigned to keyboard sustain. If sustain is not working correctly either in controller mode or in synth mode, operate the sustain pedal or footswitch and then press the 'template edit' button to access the sustain pedal input settings. Use the 'bank/page' buttons to scroll through the settings and make sure they are set as follows:
Control Type: CC
Control Nem: 64
Display Type: 0-127
Button Type: Momentary
Low Value: 127
High Value: 0
Note that these settings are for a normally closed pedal. If you have a normally open pedal set the Low Value to 0 and High Value to 127. Once you have set these press 'write' twice (synth mode) or four times (controller mode) to save the settings and then 'play/synth' to return to controller/synth mode.
In controller mode it is possible to assign the sustain pedal input to control functions other than keyboard sustain. A sustain pedal or footswitch can be used to send CC, NRPN, RPN, sysex, MMC, note on/off and program change MIDI messages. The sustain pedal input settings are stored with each template so you can change the function of the sustain pedal input from one template to another. See pages 18-22 of the X-Station user guide (available in pdf format from here) for further information on assigning controls.
In synth mode it is also possible to assign the sustain pedal input to any MIDI message you like. This allows you to control any X-Station synth parameter using a sustain pedal or footswitch by setting it to send the corresponding MIDI message. The MIDI control data for the X-Station can be found in the 'X-Station MIDI Implementation' pdf, available to download from here. As an example, to assign the sustain pedal input to arpeggiator on/off do the following:
1. Look up which MIDI message arpeggiator on/off is mapped to in the 'X-Station MIDI Implementation' pdf - it is NRPN104 values 28 (off) and 29 (on).
2. Put the X-Station into synth mode and press the 'template edit' button to enter edit mode.
3. Operate the expression pedal to bring up its settings and make sure it has the following set:
Control Type: NRPN
NRPN LSBank Num: 104
NRPN MSBank Num: 0
Display Type: 0-127
Button Type: Momentary (if you want arp to turn on only when pedal is depressed) or Toggle (if you want arp to turn on/off on alternate presses)
Low Value: 28
High Value: 29
4. Press 'write' twice whilst still in edit mode to save the settings and then press 'play/synth' to return to synth mode.
The sustain pedal input will now control arpeggiator on/off regardless of what synth patch you select because the sustain pedal input settings are saved with the synth mode template, which is recalled every time you switch into synth mode.