5.5 Connecting the OTT PLS 500 to any data logger using an
SDI-12 interface
■
Connect the OTT PLS 500 to an SDI-12 input of the data logger. Follow the data
logger handbook when doing this. Refer to Fig. 4 for the wire assignments of
the OTT PLS 500; wires used: red, blue and grey. The maximum cable length is
200 m!
Note:
In an SDI-12 bus, the supply voltage (12 volt line) is 12 volts according to
the standard, max. 16 volts. Take this into account if there are other sensors in the
SDI-12 bus in addition to the OTT PLS 500!
Refer to Chapter 5.7 or 5.8 for detailed information on connecting the
OTT PLS 500 to OTT/Sutron data loggers.
The SDI-12 commands and responses used with the OTT PLS 500 can be found in
Chapter 7, "SDI-12 Commands and Responses".
5.6 Connecting the OTT PLS 500 to any data logger/electronic
control system using an RS-485 interface
■
Connect the OTT PLS 500 to an RS-485 input of a data logger/an electronic con-
trol system. Follow the handbook of data logger/electronic control system when
doing this. Refer to Fig. 5 for the wire assignments of the OTT PLS 500;
used wires: red, blue, green and orange. The maximum cable length is 1000 m!
Required wire cross section, see Chapter 5.4.
Note on using the physical RS-485 interface:
Depending on the probe variant, the RS-485 supports the SDI-12 or the
Modbus (RTU) transmission protocol. The RS-485 interface in combination with the
SDI-12 protocol is designed and tested for use on OTT and Sutron data loggers!
OTT Hydromet provides no guarantee of functionality if you connect the OTT PLS 500
via the RS-485 interface (SDI-12 protocol) to a data logger of a third-party manu-
facturer.
Refer to Chapter 5.7 or 5.8 for detailed information on connecting the
OTT PLS 500 to OTT/Sutron data loggers.
The SDI-12 commands and responses used with the OTT PLS 500 can be found in
Chapter 7, "SDI-12 Commands and Responses"; find information on the Modbus
(RTU) transmission protocol in Chapter 8, Modbus protocol (RTU).
Fig. 4: Wires used with an SDI-12 interface
+5.5 … 28.8 V
DC
(red)
GND (blue)
SDI-12 Data
(grey)
Fig. 5: Wires used with an
RS-485 interface
+5.5 … 28.8 V
DC
(red)
GND (blue)
RS-485 A
(green)
RS-485 B
(orange)
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