Rs485 Network Connection; Rs485 (4W) Bus Connection - CEL-MAR ADA-4040PC1 User Manual

ADA-4040PC1
PC
USB
connector
USB
Fig 5. 2-Wire connecting ADA-4040PC1 to PC with the use of ADA-I9140 USB to RS485/RS422

3.3. RS485 NETWORK CONNECTION

RS485/RS422 interface in ADA-4040PC1 converter is described as: Tx+/A, Tx-/B, Rx+, Rx-. Connection of ADA-4040PC1 to
RS485(4W) and RS485(2W) network are shown bellow.

3.3.1. RS485 (4W) BUS CONNECTION

MODBUS-ASCII / MODBUS-RTU
RS485 / RS422
RS485/RS422
connector
Tx+/ A
Rt
Tx-/ B
Rx+ Tx+/ A
Rt
Rx- Tx-/ B
GND
MASTER
MODBUS-ASCII
DEVICE
Fig 6. Example connection of ADA-4040PC1 to RS485(4W) 4-wire bus and galvanic separation of SLAVE device
ADA-I9140
USB
RS485 / RS422
connector
connector
Tx+/ A
USB Tx-/ B
ADA-4040PC1
ASCII RTU
RS485/RS422
connector connector
Rx+ Tx+/ A
Rt
Rt
Rx- Tx-/ B
Rx+
Rt
Rt
Rx-
GND GND
Rx+
Rx-
GND
RS485(4W) bus
9600Bd/8/N/1
MODBUS-RTU
SLAVE-1
MODBUS-RTU
6
ADA-4040PC1
ASCII RTU
RS485 / RS422 RS485 / RS422
connector connector
Tx+ / A Tx+ / A
Tx- / B Tx- / B
Rx+ Rx+
Rx- Rx-
GND GND
SLAVE-2
MODBUS-RTU
RS485(2W)
19200/Bd/7/N/2
SLAVE-3
MODBUS-ASCII