connecting and running payment terminals on POSBox in different countries is heavily underdocumented.
this is what i know:
to connect a payment terminal you need three things:
1.
hardware: POSBox and payment terminal.
if POSBox has no free USBs port for the payment terminal you need serial connector cable. (this problem is not 100% clear).
2.
additional module on server:
"On the main Odoo server, you should install the module pos_payment_terminal."
https://www.odoo.com/apps/modules/10.0/pos_payment_terminal/
this module talks to the POSBox that it shall communicate with payment terminal.
3.
additional module on POSBox:
On the POSBox you may install a module with the right protocol for your payment terminal IN YOUR COUNTRY!
"On the POSbox, you should install the module
hw_x depending on the protocol implemented in your device."
for France, the Telium protocol seems to be running. you can use module hw_telium_payment_terminal :
https://www.odoo.com/apps/modules/8.0/hw_telium_payment_terminal/
(it is not sure whether that works on 9.0 or 10.0)
if you have other than Telium protocol (e.g. ZVT, OSI in germany) then you must ask for a module that supports that.
i have not found any other module than Telium.
--
hint: call the biggest odoo gold partner in your country and ask them directly (and provide answer here).