Question:
When a cash drawer is connected through a Parallel or Serial Receipt Printer, the cash drawer will not open.

Answer:
When a cash drawer is connected through a Parallel or Serial Receipt Printer, the code that will pop the drawer open is more dependent on the technical specifications of the printer than those of the cash drawer.

Nearly all cash drawers pop open when they receive a pulse from the printer between 250 and 500 milliseconds in duration. Thus the printer needs to issue the correct pulse.

Take the Posiflex 3100 series cash drawer, for example. A CR 3100 that is ordered with a printer daisy-chain connection may pop open with an ASCII code of "07" when used with a PP-3000 dot matrix printer. But if the printer is upgraded to a Posiflex PP-4000 thermal printer because of the increased speed and quiet operation of the thermal device, the printer will work fine, but the cash drawer will be "broken" until a different code is entered for the device.

If you take a look at the cash drawer device code "cash/therm" for Posiflex thermal printers, you will see that it is completely different than the one used for dot matrix printers. Because of this it is more useful to look in the PRINTER'S technical manual, instead of one for the cash drawer.

Nearly all cash drawers pop open when they receive a pulse from the printer between 250 and 500 milliseconds in duration, so scan the printer tech documentation for a command that will pulse the "accessory port" for this length of time and use that as a starting point for testing the device code for this new printer.
 

More Information

This tip is only useful for issues with a cash drawer that is connected through a receipt printer. Serial Cash Drawers that are directly connected to the computer should be set up according to the instructions that come with the drawer unit.