Rs485 (2W) Bus Connection; Gnd Terminals Connection; Line Termination Rt Of Rs485 Bus; Power Supply Connection - CEL-MAR ADA-11040 User Manual

ADA-11040

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.
ADA-11040
SMA con.
RF connector
RF
Power Supply

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.
CANNOT CONNECT TO THE GND TERMINAL - CABLES SCREENS, PE CIRCUIT OF ELECTRICAL INSTALLATION, SIGNALS

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
SW1-1
SW1-2

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.
RS485
Tx+
Rt
Tx-
Rx+
Rt
Rx-
GND
V-
V+
V+
V-
Fig 8. Example connection of RS485 (2W) devices to ADA-11040
GROUNDS OF OTHER DEVICES.
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
ON – enable the terminator 120 W to terminals Rx+ and Rx-
OFF – disable the terminator 120 W to terminals Rx+ and Rx-
ATTENTION!
Description
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