JUMPER ON I/O EXPANSION V5.0

Dear all,
i have bought a DFRurduino I/o expansion v5.0 shield.
I want to use it for a Modbus communication over Rs485.
I don't know how to selection jumper must be placed for select RS485 and not APC.
I have tried to see schematics but i'm not able to find a solution.
Can you help me?
i have bought a DFRurduino I/o expansion v5.0 shield.
I want to use it for a Modbus communication over Rs485.
I don't know how to selection jumper must be placed for select RS485 and not APC.
I have tried to see schematics but i'm not able to find a solution.
Can you help me?