The answer is "depends".
In Psycle, since the sound is generated by plugins, the commands are also responsibility of the plugins.
When using the sampler, the commands slide up/down and portamento to note are supported.
For other native plugins, some of them have support fo slide up/down. Check the menu "Views->Help" on the machine parameter window.
As for VSTs, the easier way is to send a midi command for pitch wheel. (example: mcm E0 00 6060 )
Or you can try the commands:
C1xx - Set pitch bend range of the VST.
C3xx - Slide to note with speed xx.
Dxyy - Pitch slide down x number of semis, yy speed.
Exyy - Pitch slide up x number of semis, yy speed.
Of course, it all depends on the VST supporting pitch wheel, but it tends to be supported.
For more information, read the file tweakings.txt included in Psycle.
<[JAZ]> Pa pi pa pa pa pi pa.... ;ĚD