CEL-MAR ADA-11040, Руководство пользователя, Страница: 9 / 16

3.4.3. RS485 (2W) BUS CONNECTION
Most of device with RS485 interface use 2-wire bus for transmission.
Before connection 2-wire RS485 bus, should be setted MODE switch to RS485 mode, located on the front panel of ADA-11040. Then
connect bus wires to connectors TX+/A, TX-/B, - as shown bellow.
Fig 8. Example connection of RS485 (2W) devices to ADA-11040
3.4.4. GND TERMINALS CONNECTION
Connection of GND terminals of RS485/422 interfaces, devices connected to RS485/422 bus, should be done in the case of a
potential difference RS485 / RS422 interfaces, which prevents proper data transmission.
ATTENTION!
CANNOT CONNECT TO THE GND TERMINAL - CABLES SCREENS, PE CIRCUIT OF ELECTRICAL INSTALLATION, SIGNALS
GROUNDS OF OTHER DEVICES.
3.4.5. LINE TERMINATION Rt OF RS485 BUS
The application of Line Termination (terminator) Rt = 120 ohms on the ends of the bus, will reduce electrical reflection in long data line
at high baud rate. It is not needed below 9600Bd. For over 1000m @ 9600Bd or 700m @ 19200Bd the line termination can be used, if
there are problems with proper transmission.
Example connection of Rt are shown on figures above. The resistor Rt = 120
W
.
ADA-11040 converter has two implemented terminators, connected to terminals Tx+/A – Tx-/B and Rx+ - Rx-, by the use SW1
microswitch (see table below).
SW1 Description
SW1-1
ON – enable the terminator 120
W
to terminals Tx+/A and Tx-/B
OFF – disable the terminator 120
W
to terminals Tx+/A and Tx-/B
SW1-2
ON – enable the terminator 120
W
to terminals Rx+ and Rx-
OFF – disable the terminator 120
W
to terminals Rx+ and Rx-
3.5. POWER SUPPLY CONNECTION
To connect power supply to the converter, should have DC power supplies (regulated) output voltage from 10 V= to 30V=, min.
nominal power 2W, e.g. DR-15-24. Power cable from DC power supplies to device can not be longer than 3m. Should connect positive
(+) end of DC power supplies to V+ device terminal and negative (-) end to V- on terminal block. ADA-11040 has protection against
power supply reverse connection.
9
ADA-11040
Power Supply
Rt
Rx+
Rx-
GND
Tx+
Tx-
V+
V-
RF
V-
V+
SMA con.
RF
RS485
connector
ADA-11040
Rt