So far I have not seen an out-of-the-box plug in for that but if you are a developer I would say . .It is a common integration pattern to send back& forth the sub-set of traasactions for sales and inventory (using xml messages, queues) for instance from ERP to POS similar like ERP -> Online stores
For the simplest approach I would suggest you red one's plugin as seed for your integration...... (xml, activemq)
A more powerful approach would be to use the Idempiere -> SmartPOS integration (rabbbitMQ source code repos available in sourceforge ? bitbucket)
If you do not have the integration skills, perhaps some companies with that integration background (like SmartJSP) can help you, to re-use that work, and create the remaining part for prestashop ...which would be less work than start from scratch and we can share that with the community ...
Regards,
Pedro R