Build a bridge software between "CashKeeper" and our POS Software

One of our customers needs to use a "Cash Keeper" ([login to view URL]) with 2 POS. We need a software (executable with an installer) to make the link between the 2 POS and the "Cash Keeper" machine. This software will be installed on one of the point of sale machine, running Windows. Needed features : - Listen to the 2 POS at the same time - Display state (connected / not connected / in use) of the CashKeeper and the 2 POS - Receive charge orders from the POS, send it to the CashKeeper and return back the answer to the POS (OK and details, or ERROR and explanations) Cashkeeper <=> POS communication : - The link between the POS and the bridge software will be by socket in JSON format. - The bridge software must handle the state of use of the cashkeeper machine. If already in use by the other POS, the call will be forbidden. Once the other POS finished the operation, the second POS will be able to communicate with the CashKeeper. Provided elements : - Virtual Cashkeeper - Cashkeeper test/demo program (Visual basic) with connection, payment and others functions - Cashkeeper integrator manual Thanks