Here is a demo video of the integration I implemented for one of our customers between a cash drawer and Lawson Smart Office using a Script. (If you want to skip the talk, jump to time stamp 3:31 in the video to see the cash drawer open.)
The result is a single cash drawer controlled by multiple Points of Sales throughout the showroom. Each Point of Sales runs Smart Office. The solution requires authorization (who can access the cash drawer) and auditing (who opened the cash drawer when) for security purposes. For the user its just a click on a new button Open Register.
I implemented the solution as client/server: the clients are Personalized Scripts in JScript.NET for Smart Office, the server is a custom Java program connected to the cash drawer with JavaPOS and a Serial cable, a custom bridge between .NET and Java made with a tiny HTTP server, and Properties file.