User Guide

2.3.2 Serial interface
1. Interface RS-422-compatible serial interface.
2. Data transfer speed 57.6 (default), 444, 888 kbit/s
3. Data format Start bit: 1 bit
Data: 8 bits
Stop bit: 1 bit
Parity: None
4. Signal polarity MARK (logical "1"): -3V to -12V
SPACE (logical "0"): +3V to +12V
5. Interface connectors On printer: Female 8-pin mini-DIN connector
On cable: Male 8-pin mini-DIN connector
6. Input/output signals and pin layout
7. Description of signals
SCLK (signal clock)
This pin outputs a sync clock when data transfer speed is set to 442.2 and 884.4
kbit/s.
TXD-/TXD+ (transmitted data)
Output signals TXD- and TXD+ are the differential signals for sending data from the
printer. TXD- is in the MARK state (logical "1") when no data is being sent; TXD+ is
in the SPACE state (logical "0"). These signals are used to send the printer status,
etc., to the host computer.
RXD-/RXD+ (received data)
Input signals RXD- and RXD+ are the differential signals for the printer to receive
data. RXD- is in the MARK state (logical "1") when no data is being sent; RXD+ is in
the SPACE state (logical "0"). These signals are used to receive the control
commands and print data sent from the host computer to the printer.
PG (protection ground)
PG is a low-impedance ground for the interface cable shielding.
2-19
BJC-8500
Part 2: Product Specifications
876
5
4
3
12
Pin No.
1
2
3
4
5
6
7
8
Shield
Signal
SCLK
N.C.*
1
TXD-
S-GND
RXD-
TXD+
N.C.
RXD+
PG
I/O
OUT
OUT
IN
OUT
IN
*1. N.C. means no connection