beautypg.com

FUJITSU C145-C037-01EN User Manual

Page 63

background image

5-15

5.4.3

Serial data format

The format of 10-bit or 11-bit serial data, given in Figure 5.12, consists of a start bit, data bits, a parity bit, and stop

bits. A bit is in the mark state when not being transmitted. Data bits start with the least significant bit (LSB). For

example, the character “K” (hexadecimal 4B) is transmitted as shown in Figure 5.12 (7 data bits, even parity).

Start

bit

Parity

bit

Stop

bit(s)

Data bits

High, +, or Space

Low, –, or Mark

0

0

0

0

0

1

1

1

1

3

5

6

1

2

4

7

1

(1)

Figure 5.12 RS-232C data format

5.4.4

Cable connection diagrams

The connector at the printer side is a 9-pin type. The connector at the computer side is a 9-pin type or a 25-pin type.

CD

RD

TD

DTR

SG

DSR

RTS

CTS

RI

FG

RTS

TD

RD

DSR

SG

DTR

#

DTR

#

Shell

(pin 8)

(pin 3)

(pin 2)

(pin 20)

(pin 7)

(pin 6)

(pin 4)

(pin 5)

(pin 22)

(pin 1)

Shell

Computer (DTE)

Printer (DTE)

# Open wire

(pin 1)

(pin 2)

(pin 3)

(pin 4)

(pin 5)

(pin 6)

(pin 7)

(pin 8)

(pin 9)

Figure 5.13a Example of RS-232C cable wiring (25-pin connector at computer side)