FTS 21216, Руководство по эксплуатации

Страница: 13 / 54

700-SDI-RADAR-LX-80-Man Rev 1 08 Oct 2021 8 /49
3.2 SDI-12 INTERFACE
SDI-12 interface is widely used to connect hydrological equipment to dataloggers. SDI-12 uses a
single communication line, and very slow speed communication to enable the use of very long
communication cables.
For hydrological applications, SDI-12 communication interface is a valid option and the instrument is
natively able to communicate directly with SDI-12 master devices (dataloggers etc.).
The device supports SDI-12 protocols version 1.3. The device is not an SDI-12 slave; however, it
responds to SDI-12 commands as expected from an SDI-12 slave. When operating the SDI-12
interface, low power mode is not supported: the radar works continuously (does not have
sleep/waking cycles).
3.3 SERIAL RS-232 INTERFACE
Serial RS-232 interface is implemented as standard PC full-duplex serial interface with voltage levels
adequate for direct connection to PC computers or other embedded devices used for serial RS-232
communication.
3.4 SERIAL RS-484 INTERFACE
Serial RS-485 interface is implemented as standard industrial half-duplex communication interface.
The most common communication protocol used with RS-485 interface is Modbus-RTU.
The communication interface is internally short-circuited, and overvoltage protected. Depending on
the receiving device, the interface can be used with only two wires (D+ dark red wire & D- orange
wire) while in some cases the ground connection (signal GND grey wire) is also required. For more
details please consult the specifications of the receiving device.
3.5 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 connecting the LX-80 to PLCs,