Modbus communication: Wiring diagram for conversion of RS-485 2 wire to 4 wire

Industrial Automation
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Modbus communication: Wiring diagram for conversion of RS-485 2 wire to 4 wire.

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I am trying to connect Floboss 107 to CentumVP (ALR121) but no success. (Wiring Diagram attached)

Can anybody help me?

Fb107 - CentumVP ALR121 Serial Wiring.png838×555 6.43 KB

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Positive to Positive: TX+/RX+ connects to A Negative to Negative: Tx-/Rx- connects to B

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This connection was working.