3.4. EXAMPLE CONNECTION OF DEVICES TO THE CONVERTER
Using the ADA-1020 can be separated the RS232 computer port from the devices and extend the RS232 computer port (TX, RX
signals), even up to few kilometres. Example connection is shown below (fig.9)
For this type of connection (extending the RS232 computer ports), should be done according to below figure.
On the converters with 0-20mA active/passive transmitter the TX switch should be set in ACT position
Fig 9. Connection of two ADA-1020 for extension the RS232 computer port
3.5. CONNECTION OF RS232 INTERFACE DEVICES TO CURRENT LOOP BUS
Using ADA-1020 in the version with Active/Passive current loop transmitter ( I= 0-20 mA), can be created the current loop bus as on
the figures below.
3.5.1. CONNECTION OF 15 RS232 INTERFACE DEVICES TO CURRENT LOOP BUS
In this case/example the Current Loop bus is created by one ADA-1020 converter (MASTER
– active transmitter
) and one ADA-1020
converter (SLAVE
– active transmitter
- the furthest located from the MASTER) and max. 14 converters ADA-1020 (SLAVE –
passive transmitter
). The number of the SLAVE converters can be less for long lines. Example of connection is shown below.
8
ADA-1020
RS232 extended port of
PC : Tx, Rx
RxD -2
TxD -3
DTR -4
DSR -6
RTS -7
CTS -8
PC
SG -5
RS232
DTE/DB-9M
ADA-1020
Current Loop
Vss+
Vss-
Power
Supply
RS232
DCE/DB-9F
CTS -7
RTS -8
GND -5
Vss-
Vss+
Tx -2
Rx -3
DSR -4
DTR -6
Tx+
Tx-
Rx+
Rx-
2
3
4
6
7
8
5
CAB-DB 9F/DB9M-S-1,8m cable
Socked
DB-9F
2
3
4
6
7
8
5
Plug
DB-9M
Rx+*
Tx+
Tx-
Rx+*
Rx-
ADA-1020
Current Loop
Vss+
Vss-
RS232
DCE/DB-9F
Tx -2
Rx -3
DSR -4
DTR -6
CTS -7
RTS -8
GND -5
Vss-
Vss+
Cable / Adapter
CAB-DB9M/BD9M-C-2m /
ADP-DB9M/DB9M-C
2
3
4
6
7
8
5
Plug
DB-9M
2
3
4
6
7
8
5
Plug
DB-9M
Rx+
Power
Supply
Current Loop Line
2-pair twisted
