Citizen LinkServer helps you to set up Citizen label printers via USB. [Supported models] Designated printer models, firmware versions are required (see below). - CL-E300 (Firmware Version: EQxx0300 or later) - CL-E300EX - CL-E321 (Firmware Version: EQxx0300 or later) - CL-E321EX - CL-E303 (Firmware Version: ERxx0300 or later) - CL-E303EX - CL-E331 (Firmware Version: ERxx0300 or later) - CL-E331EX - CL-S521II - CL-S531II - CL-S621II - CL-S631II - CL-S700II - CL-S703II - CL-S6621 - CL-S700III - CL-S703III [Supported interface type] - USB The Android device must work as USB host to control the printer device. For example, you will need a so-called USB OTG (On-The-Go) adapter, which has a micro USB or Type-C male connector on the Android side (depending on your Android device) and a Type-A female connector on the other side. Then you can connect a regular USB cable for printer which has a Type-A male and Type-B male to connect to a printer. [Example features] - Checking printer information such as serial number or counters. - Setting up printing controls such as printing speed, darkness or position. - Setting up systems such as sensor levels or buzzer. - Setting up media handlings such as cutter action. - Setting up communication interface. - Switching configuration presets. - Managing access control. - Printing test labels. - Sending raw data to the printer. - Updating firmware. - Resetting the printer. - Restarting the printer. - Switching emulations.