A cash drawer connects to your receipt printer and opens when you finish a cash or a check (cheque) transaction while the printer prints the receipt. Learn more: Add Cash Registers
To set up a cash drawer with your iPad:
Plug the RJ12 connector cable from the cash drawer into the receipt printer.
Open the Vend Register app and tap the menu button to open the sidebar menu.
Tap Settings and select Hardware.
Select the printer you want to attach to the cash drawer.
On the Printer Settings page in Register, update Cash drawer enabled to On.
Update Open cash drawer on Sale to On.
Your cash drawer is now set up for your iPad.