Karel MS128 - Page 31

Karel MS128 Installation & Maintenance Guide
Edition 3.2
25
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PC REQUIREMENTS
:
The PC to be used with MS128 system should have the following
specifications:
a) 640 KB RAM (at least)
b) Windows (not older than version 3.1)
c) A harddisk
d) A serial port
•
SIGNALING AND COMMUNICATION PARAMETERS :
The signaling between the system and the PC is illustrated in the following
table. Since the PC-Exchange cable has a 25-pin plug at the PC end, it is
necessary to employ a 25-pin to 9-pin converter plug, in order to use the 9-pin
connector of the PC.
CPU128 Card PC
Connector No Signal 25-pin connector
Pin No
9-pin connector
Pin No
2 + 10 VDC 3 2
3 - 10VDC 2 3
4 TXD 20 4
5 RXD 7 5
7 GND 4 7
The signal names above are given with respect to MS128 system and these
pin assignments are valid only for IBM compatible devices. If your device is not
IBM compatible, then you must provide the requested pin connections to
match the signaling parameters of the system.
The communication protocol for PC - Exchange connection is illustrated in the
following table:
For PC
Data Bits 8
Stop Bit 1
Parity None
Baud Rate 4800 Bps
The CM128 and PK128 modules are able to set the communication protocol to
the appropriate values, automatically.
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D
ATA FORMAT OF
CM128 :
A call record consists of two lines, each followed by Carriage return (0Dh) and
Line Feed (0Ah) characters.