1) A printer drive is not installed adequately.

- The USB printer class driver and the virtual COM driver follows USB interface functions.   A printer driver should be installed after a virtual COM driver has been installed.   Note that the output port is COMx, not an USB port.

2) One PC is connected with 2 or more USB printers.

-  The factory default setting serial number is [00000000]. Printers with the same serial number cause a PC hang up when the printers are connected with the same PC.

You need to register different serial numbers to each printer. Note that each printer demands each different printer driver on Windows.

3) Trouble with a connected cable.

- Replace to another cable if your cable is not enough to measure against noise (plating on a connector, ferrite core etc.). The standard recommends 5 or below meters, but it should be as short as possible.

4) Not directly connected with a PC.

- We cannot guarantee an operation if your printer is connected with an USC conversion cable through serial or parallel.

- Make sure that your printer be connected with an USB port of a PC, not through an USB hub. Because a printer may not work adequately due to other devices connected with the hub.