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RS485 SERIAL COMMUNICATION
If the RS485 network exceeds 100 metres in length or baud-rate
over 9600 are used, two terminating resistors are needed at the
ends of the network: close the two jumpers indicated in the picture
on the furthest instruments. Should there be different instruments
or converters, refer to the specific manuals to determine whether it
is necessary to connect the above-mentioned resistors.
DIRECT CONNECTION BETWEEN RS485 AND RS232 WITHOUT CONVERTER
Since a two-wire RS485 output may be used directly on the RS-232 input of a PC or remote display
or printer, it is possible to implement instrument connection to an RS-232 port in the following
manner:
INSTRUMENT
RS232
RS485
–
→
RXD
RS485 +
→
GND
This type of connection allows A SINGLE instrument to be used in a ONE WAY
mode.
INSTRUMENT
RS485 +
RS485 -
max 500 m
RS485 +
3 2
5
PC RS232
RX+
RX-
TX-
TX+
CONVLAU
24 VDC
+
-
0
TX
RX
VIN
RS485 +
RS485 -
RS48
5 -
RS485 +
RS48
5 -
RS485 +
RS48
5 -
GND
GND
GND
INSTRUMENT
INSTRUMENT
