TOOL CHANGER , EMC AND STG2

Hi friends!

I am unable to find tool changer option in EMC. There isnt any tool
changer related input and output ports defined in ini.
I've started browsing the sources of emc. i've seen some of the c
code files contain some wraper functions related with tool change

Can somebody guide me if i implement the tool change functionality
in emc then what source files i might need to edit? and what
challenges and difficulties i might face during this work?

also if somebody could guide me about how and at what level the tool
changer fucntionality is implemented at the moment in emc?

Thanks and best regards

Asim