C1300
Advanced Circular Chart Recorder
2 Electrical Installation
IM/C1300–MOD
Rev. C
3
2 Electrical Installation
2.1 Selection of Serial Communication Adaptors for Personal Computers
An RS422/485 communications adaptor is required for serial links. Ensure that the card used has galvanic isolation to protect the
computer from lightning damage and increase its immunity to noise pick-up.
2.2 Recommended OPTO22 Boards
The following OPTO22 boards are recommended for use with the C1300:
2.3 Pull-up and Pull-down Resistors
o prevent false triggering of the slave (C1300) by the presence of noise when the master (host computer) is inactive, 1.8k
pull-up
and pull-down resistors must be fitted to the RS422/485 adaptor card – see Figs. 2.1 and 2.2.
Note.
An RS422/485 communication board is required in the host PC.
Observe the limitations outlined in the Installation Guide – the maximum serial data transmission line length for both RS422
and RS485 systems is 1200m (3,937 ft).
Part No.
Computer Type
AC24 AT
AT Bus IBM® PC compatible
AC34
Microchannel IBM® PC
Fig. 2.1 Pull-up and Pull-down Resistors (3-wire Operation)
Tx+
Tx
GND
+5V
0V
Computer Terminal or Host Computer
Rx
Rx+
Tx
Tx+
'A'
'B'
1
2
7
8
9
3
4
5
6
Serial Module
Terminal Board
C1300
Pull-up and Pull-down Resistors
+5V
1.8k
W
Pull-up Resistor
1.8k
W
Pull-down Resistor
'A'
'B'
5
8
6
7
3
10
4
9
Linked In
see
Note
Linked Out
+5V
0V
1.8k
W
Pull-up
Resistor
1.8k
W
Pull-down
Resistor
'A
'B'
'A'
'B'
Links on Serial Module
Tx+/Rx+
Tx/Rx
PL2
PL2
GND
Note.
If an RS422/485 adaptor card without pull-up and
pull-down resistors is used, the C1300's internal resistors
can be linked in.
