700-SDI-RADAR-300WL-Man Rev 2 11 Apr Mar 2022
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Part# 21371
2.11
SERIAL RS-485 INTERFACE
Serial RS-485 interface is implemented as standard industrial half-duplex communication interface.
Communication interface is internally protected against short-circuit and overvoltage. Depending on
the receiving device interface can be used with only two wires (D+ dark red wire & D- orange wire) or
in some cases ground connection (signal GND gray wire) is also required. For more details, consult
the receiver specification.
Most common communication protocol used with RS-485 interface is Modbus-RTU but other
protocols are also available. Details of communication protocols are described later in this manual.
2.12
ANALOG 4-20 MA OUTPUT
Analog current 4 – 20 mA output is provided for easier compatibility with older logging and control
systems. Output is implemented as current sink architecture with common ground. Maximal voltage
applied to the sink can go up to 30 VDC providing greater flexibility in connection of the sensor to
PLCs, loggers, or data concentrators.
Signal range and function for 4 – 20 mA analog output can be configured in the setup application so
the sensor will be able to signal the best suitable value range with the available current range.
The sensor’s current step has a limiting resolution of 0.3 μA. Ensure the minimal and maximal
values representing 4 mA and 20 mA have sufficient resolution for system requirements.
