3
3
INSTALLATION
Observe the limitations outlined in the
Operating Instructions (IM/C300). The
maximum serial data transmission line
length for both RS422 and RS485 systems is
1200m.
3.1 Serial Communication
Adaptors for Personal Computers
An RS422/485 communications adaptor
board is required for serial links. It is strongly
recommended that the card used has
galvanic isolation to protect the computer
from lightning damage and increase
immunity from noise pick-up from cables.
The following OPTO22 boards are
recommended for use with the C300 serial
instruments.
Part No.
Computer Type
AC24
XT Bus IBM PC compatible
AC24 AT
AT Bus IBM PC compatible
AC34
Microchannel IBM PC.
The
following‘Jumper’ selections are
required on OPTO22 boards (usually
supplied as the default configuration):
RX & TX
install line termination
jumper
Install pull-up and pull-
down jumpers
CTS & RTS
disable jumper installed.
Select board address and interrupts as
described in the OPTO22 manual.
4
ELECTRICAL CONNECTIONS
All connections, apart from those for serial
data communication, are made as shown in
Table 4.2 in the Operating Instructions
(IM/C300).
4.1
Serial
Connections – Figs. 4.1 and 4.2
The controllers must be connected in parallel
as shown in the schematic diagram – Fig.
4.2. The RS485 standard quotes connection
of thirty two slaves (C300 Controllers)
maximum to any single driver (computer
terminal or host computer); the RS422
standard quotes connection of up to ten
slaves. However, these numbers can be
increased if the driver’s serial port permits.
Make serial data connections as shown in
Fig. 4.1. The type of cable used is dependent
on the transmission speed and cable length:
Up to 6m (all speeds)
– standard
screened or twisted pair cable.
Up to 300m
– twin twisted pair with
overall foil screen and an integral drain
wire, e.g. Belden 9502 or equivalent
Up to 1200m
– twin twisted pair with
separate foil screens and integral drain
wires for each pair, e.g. Belden 9729 or
equivalent.
Computer Terminal or
Host Computer
Chain of Controllers Connected
Last C300 Controller
in Chain
Termination Resistor
(on C300's receive input)
Fig. 4.2 Schematic Diagram
