To set up your printer to automatically open the cash drawer, please follow these steps:
Plug the RJ12 connector from your cash drawer to the printer
Head to the “Device and Printers” (Settings-> Device-> Device and Printers)
Click on the Star TSP100 cutter (Star TSp143LAN cutter) and choose the Printer properties
After the Printer properties popup shows, click on Change Properties button
Set the Peripheral Unit Type into the Cash Drawer and the Peripheral Unit 1 and 2 into the Document Bottom
Click on the OK button to complete the setup.