GK888t Desktop Thermal Printer User Guide

Serial Port Interface

Configurations for the Serial Port Interface are described here.

Serial Port Signal Description
Pin	Description
1	Not used
2	RXD (receive data) input to the printer
3	TXD (transmit data) output from the printer
4	DTR (data terminal ready) output from the printer -- controls when the host may send data
5	Chassis ground
6	DSR (data set ready) input to the printer
7	RTS (request to send) output from the printer -- always in the ACTIVE condition when the printer is turned on
8	CTS (clear to send) - Not used by the printer
9	+5 V @ 0.75 A fused

The maximum current available through the serial and/or parallel port is not to exceed a total of 0.75 Amps.

When XON/XOFF handshaking is selected, data flow is controlled by the ASCII control codes DC1 (XON) and DC3 (XOFF). The DTR control lead will have no effect.

Interconnecting to DCE Devices—When the printer is connected via its RS-232 interface to data communication equipment (DCE) such as a modem, a STANDARD RS-232 (straight-through) interface cable must be used. The figure below shows the connections required for this cable.

Connecting the Printer to a DCE Device
DB-25S Connector to DCE Device		DB-9P Connector to Printer		DB-9S Connector to DCE Device		DB-9P Connector to Printer

Connecting to the KDU (Keyboard Display Unit)—The KDU was designed for DCE printer connections and requires a Zebra custom serial port gender-changing adapter. The KDU now includes the KDU adapter and the Zebra kit part number for the KDU Adapter is 105934-088.