Lexmark 248X ユーザーズマニュアル

Section 6: Using the Printer Interface

The following illustration shows the RS-232C serial cable:

2

TXD
(Transmit Data)

This line transmits data from the printer to the host. The data 
characteristics are specified by the function menu settings which are 
read only during a Power On Reset (POR). The only data 
transmitted are XON (x’11’) and XOFF (x’13’) signals. Transmission 
occurs only when CTS is high.

3

RXD
(Receive Data)

This line receives data from the host. The serial interface accepts 
data only when DSR is On. 

4

RTS
(Request to Send)

This line is set high and remains high even after the serial interface 
finishes its POR.

5

CTS
(Clear to Send)

This line is monitored only if the XON/XOFF protocol is selected 
because transmission occurs only when CTS is high.

6

DSR
(Data Set Ready)

DSR is another method of providing data integrity. Data is accepted 
only when DSR is high.

20

DTR
(Data Terminal Ready)

This line is set high after the serial interface finishes its POR 
sequence. However, if you select DTR pacing handshake protocol, 
this line is used to indicate to the host whether or not the printer is 
ready to receive any more data.

25-Pin 
Male 

25-Pin 
D-shell 
Female

13

25

1

14

25

13

14

1

Serial Adapter Side

Computer Side