XLINK 500/100 Operations & Maintenance Manual page # 81
TB/DIG IN 2
The system keeps a tally for each of the two counter inputs. The tally is stored in persistent
memory, meaning that counts are not lost when power is removed. To reset the counts, calibrate
one of the counter measurements to zero.
The system keeps counting even when Recording is OFF, as long as there are active
measurements set up that use the counter inputs.
When a count measurement is calibrated, the count tally for that input is set to zero, and the
measurement's Offset is to the calibrated value. For example, setting Precip Accumulation
reading to 10.2 will clear the tally for TB/DIG IN 2, and set the measurement's Offset to 10.2.
9.3.3.
Measure Type: SDI-12
SDI-12 sensors traditionally connect over the SDI-12 bus:
SDI-12 Port: Terminals #14 Ground, #15 +12V, and #16 DATA.
Please note: The SDI-12 port is independent with is12V power and Data
connections. Power is limited to 500mA. Sensors that use more than 500mA (such as
bubblers) must connect to an independent power supply.
SDI-12 is a standardized three wire digital interface. Many manufacturers provide SDI-12 sensors
that measure different environmental effects. SDI-12 sensors provide digital data which improves
their reliability and accuracy in terms of logger sensor communications.
For details on SDI-12, please see the section
Some sensors allow for the SDI-12 protocol to be used over the RS-485 bus in order to support
extended cable lengths. These sensors use the following connection:
RS485 Port: Terminals #5 RS485-A and #6 RS485-B
SDI-12 Port
SDI-12 sensors can be assigned to Port1, Port2 or RS485. Remember that multiple sensors can
be connected to either bus as long as each sensor has a unique address. Use RS-485 when you
need long cable runs to the sensor and the sensor supports SDI-12 over RS-485.
SDI-12 Address
Multiple sensors can be connected to the same SDI-12 bus. However, each sensor needs a
unique address. The address is a single ASCII character. Most sensors default with the address 0.
If you are connecting several sensors, connect them one at a time. As each sensor is connected,
issue the 0Ax! command, chan
ging the sensor’s address from 0 to x, where x is a unique number
or letter of your choice.
SDI-12 Command
Select the desired SDI-12 command from the drop-down list or enter a unique command into the
text box. The drop-down list includes M!, M1!, MC!, C!, CC!, M2!. Consult the operating manual
for the sensor to know what command to use. The software automatically adds the address
when issuing the command. The software also automatically issues the commands to retrieve
the data after the measurement command is issued.
