Sterling Scale 820 User Manual
Page 14
DW800/820 Operation Manual
PRINTERS
Page 11
Serial Interface
The DW800/820 has the capability of using one of the following serial interface: RS-232,
RS-422, RS-485, and 20 mA Current Loop. These serial interfaces allow the indicator to be
connected to many different types of serial devices such as printers, computers, and
scoreboards. The standard DW800/820 is equipped with the most common of the serial
interfaces, RS-232.
Output Protocol Format
Baud Rate
150 to 19, 200
Parameter
Start Bits
1
Fixed
Date Bits
7 or 8
Parameter
Parity
None, Odd, or Even
Parameter
Stop Bits
1
Fixed
The format of the serial data is controlled using the following parameters: Baud Rate, Parity,
and Data Bits.
RS-232
The RS-232 interface is the most commonly used of all serial interfaces and is standard on the
DW800/820. It is used in point-to-point communications where the transmission line is less
than 50 feet. If the RS-232 interface is to be used then the Serial interface parameter must be
set to RS-232
(See Parameter Setup).
Flow control may be used with this interface to regulate the flow of data between the
DW800/820 and another serial device. To enable flow control, set the Flow Control parameter
to True (
See Parameter Setup)
and Jumper J8 to CTS. The Clear To Send (CTS) input must
then be connected to the compatible flow control output, usually Data Terminal Ready (DTR)
or Request To Send (RTS). The DW800/820 will now only transmit when CTS is high.
RS-232 Connector Pin Assignments
Pin
Name
Description
01
ZERO
External zero
02
Do not connect
03
Do not connect
04
RxD
Receive data (input)
05
TxD
Transmit data (output)
06
DTR
Data Terminal Ready (output)
07
CTS
Clear To Send (input)
_____________________________________________________________________________________________________________
Revision 4.3 Copyright ©2004 Sterling Scale Co., Inc. May 2004
Web Site:
E-mail: [email protected]