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Physical description

"RS-485 to USB adapter" is used for connecting Modbus RTU devices/meters/sensors to Vutlan VT900 and VT960 monitoring units.

Connection

Image RemovedImage RemovedImage RemovedImage RemovedImage RemovedPlease read article Connecting Modbus devices first.

Example 1: Using "RS485 to USB adapter" with internal termination.

• Sensors are connected in a daisy chain connection.
• 120Ω resistor is used at the end of the chain.
  
• Twisted pair cable is used for A(+) and B(-).
• "RS-485 to USB adapter" has an internal termination and it is switched ON.
• The data is transferred to Vutlan monitoring unit using USB port.
• Up to 31 devices can be used.
• Overall cable length no more than 1000 meters.

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Example 2: Using "RS485 to USB adapter" withiout internal termination.

• The same as the first example with the exception that the "RS-485 to USB adapter" does not have a built in termination.
• T ermination (120Ω resistor) is added at the start of the chain.

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