You can use spc_request_dev or spc_request_sys function of the SPC library when setting or using a smart expansion board.

spc_request_dev($sid, $cmd)
spc_request_sys($sid, $cmd)

Common Commands of Smart Expansion Boards

The commands commonly supported by all smart expansion boards use the spc_request_sys function.
The following is a list of smart expansion board common commands.

Command Option Description
get did get a device ID
get uid get a unique ID

PES-2401 Commands

The commands that apply to each smart expansion board use the spc_request_dev function.
The following is a list of commands supported by the PES-2401.

Command Option Description
set $port output $level turn a specified port ON(high) or OFF(low)
set $port delay $time set a delay on a specified port
get $port output get status of a specified port