Beijing Star Instrument Technology Co., Ltd
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www.star-itech.com
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7.2 Data
Interface
Features:
•
EIA RS-232C / TTL(jumper setting internal, default:RS-232C)
•
D-Sub 9pin, male
•
Asynchronous, bi-directional, half duplex
•
Baud rate: 110, 300, 600, 1200, 2400, 4800, 9600, 19200, 38400,
57600, 115200
•
Parity: None, Odd, Even
•
Data bits: 7bit, 8bit
•
Stop bits: 1stop, 2stop
•
Handshake: None, DTR/CTS, DTR/DSR, XON/XOFF
Data frame format example (7bit, 1stop, odd or even parity)
:
D-Sub 9pin assignments
Pin No. Signal
Direction
Description
1 NC
No
connection
2 RXD
Input
Receive
data
3 TXD
Output
Transmit
data
4
DTR
Output
Data terminal ready
5 SG
Signal
ground
6
DSR
Input
Data set ready
7
RTS
Output
Request to send(Connect to pin4
internal)
8
CTS
Input
Clear to send
9 NC
No
connection
Note: The pin7 (RTS) is connected to pin4 (DTR) internally.
Handshake protocol:
None:
Printer and balance can transmit data any time.
XON/XOFF
1
:
Once <XOFF> is received, it prevents further transmission of
data, the data will be stored in the transmit buffer
2
until <XON> is received.
DTR/CTS:
When the device (balance or printer) can receive data, set the DTR
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