Serial Port Interface

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

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 DTE Devices—The printer is configured as data terminal equipment (DTE). To connect the printer to other DTE devices (such as the serial port of a personal computer), use an RS-232 null modem (crossover) cable. Table 2 shows the required cable connections.

Connecting the Printer to a DTE Device

DB-25S Connector to DTE Device (PC)		DB-9P Connector to Printer		DB-9S Connector to DTE Device (PC)		DB-9P Connector to Printer

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. Figure 32 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.