Yes, specific models allow up to 40 inputs and 16 outputs from 4 GPIO modules. (PIO-102)
How to setup:
1. connect 4 GPIO modules to a USB hub and then connect this hub to the player.
2. adjust the dip switches on each GPIO module to distinguish their triggering signals:
|X in GPIX0~GPIX9 and GPOX0~GPOX3
For example, the first module's switches should be set to OFF and OFF, and the triggering GPI variable names in SMIL are GPI0~GPI9 ( where GPO variable are GPO0~GPO3 )
the second module's switches should be set to OFF and ON, and the triggering GPI variable names are GPI10~GPI19 ( where GPO variable are GPO10~GPO13 ) and so on for the third and forth modules.