Chapter 1. General - Sharp ER-A57R1 Service Manual

WHAT IS AN RS-232 INTERFACE?
•
EIA (Electronics Industries Association) standard RS-232 is asso-
ciated with the transfer of binary serial data, control signals and
timing signals between modems and data terminals.
•
The RS-232 interface is one of the devices generally used for the
exchange of information between a computer and a peripheral
device.
•
This interface (ER-A5RS) was designed to conform to the EIA
standard, but in particular it was designed for connection between
the ER-A570 and a data processing machine.
•
It becomes necessary to set communication specifications of the
ER-A5RS (e.g. baud rate) matched to those of the data processing
machine, when the ER-A5RS is connected with a data processing
machine that is equipped with the RS-232 interface.
•
The Dip switch on the ER-A5RS interface circuit board must be
used to choose the specifications.
•
Refer to Section 3 "RS-232 Interface Specifications" for details of
communication specifications.

CHAPTER 1. GENERAL

This option (ER-A57R1 and ER-A5RS) is the RS-232 interface option
for the ER-A570 cash register. It enables the ER-A570 to perform
on-line data communications.
When this option is used for on-line data communications, the ER-
A570 can be connected to a host computer. Also, their connection
can be made via modems.
When this option is used together with a multiplexer (to be procured
in the market), it allows the host computer to be connected to more
than one ER-A570.
CHAPTER 2. COMPONENTS
ER-A5RS
NO NAME
PWB UNIT
1
BRACKET
2
SCREW (FOR PWB AND
3
BRACKET)
SCREW (FOR HOLDING OF
4 THE PWB BRACKET, AND
BRACKET TO BRACKET)
SCREW (FOR HOLDING OF
5
THE RS-232 CABLE CORE)
6 WIRING TIE
CLAMP
7
(FOR RS-232 CABLE)
SPACER
8
FERRITE CORE
9
(FOR EXTERNAL CABLE)
PARTS CODE Q'ty
C PWB S 7 2 9 2 R C 0 1
1
L A N G T 7 4 6 6 R C Z Z 1
L X – B Z 6 6 6 5 R C Z Z 2
L X – B Z 6 7 7 4 R C Z Z 3
X H B S D 3 0 P 0 8 0 0 0
2
L B N D J 2 0 0 4 S C Z Z 1
L H L DW6 8 1 4 R C Z Z 2
P S P A N 7 0 3 9 X C Z Z
1
R C O R F 6 6 5 8 R C Z Z 2
CHAPTER 3. SPECIFICATIONS OF
RS-232 INTERFACE
1. Online interface
a) Interface
b) Duplex type
c) Line configuration
d) Data rate
e) Synchronizing mode : Asynchronous
f) Parity check
g) Code
h) Bit sequence
i) Data format
b1 b2
Start-bit
j) Protocol
k) Transmission line :
Cable
Connector
(ECR side)
Connector cover : Shielded cover
The table shows the relationship between the data rate and the rec-
ommended cable length.
Data rate
19,200 bps
9,600 bps
4,800 bps
2,400 bps
1,200 bps
2 ™ 2
: RS-232
: Half-duplex / Full-duplex
: Direct connection/Modem connection
: 19200, 9600, 4800, 2400, 1200, 600 and
300 bps
(Programable)
: Vertical parity check (odd)
: ASCII
: LSB first
: 1 start bit + 7 data bits + 1 parity +
1 stop bit
b3 b4 b5 b6 b7 P
Data-bit Parity-bit Stop-bit
: Polling/selecting (Simple procedure)
: Shielded cable
: D-sub 9 pin (female type) connector
Inch pitch (4-40 UNC) lock screw
Recommended cable length
3.75 meters
7.5 meters
15 meters
30 meters
60 meters