Bringing the Benefits of Real-Time Data Collection to the World
Sutron Corporation, 22400 Davis Drive, Sterling, Virginia 20164-4444
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8. Troubleshooting and Maintenance
Troubleshooting
The following checklist will help in troubleshooting problems:
Problem
Possible Cause
No data
Faulty wiring -- check all wiring and terminations
No power -- check fuse in the data recorder and power at
sensor. There is no fuse in the sensor itself.
Wrong address requested -- make sure the data recorder is set
up to request data at the proper address
Wrong address set in sensor -- use the identify command to
make sure the sensor is responding to the proper address, if
not double check internal address dip switches since on
power-up they override any address set by the software.
Command or address is wrong case -- all ACCUBAR
®
commands are capital letters, make sure address is proper
case and commands are upper case.
With RS-232, make sure that Transmit and Receive Data are
not reversed.
Garbled data
Multiple sensors set to the same address -- check address
settings of all SDI sensors. Remove all other sensors from
the recorder and add them one at a time. Communication is
defined to be 1200, E, 7, 1.
Command issued to a wild card address (* or ?). Remove all
other sensors from the recorder and try again.
Erroneous data
Wrong units selected -- use the M command and look at the
units field. Verify that the desired units are selected.
Erroneous offset entered -- display the elevation offset using
the M3 command and verify it. Re-calibrate the offset.
Erroneous user scale and offset entered -- display the user
scale and offset using the M3 command and verify.
CAUTION: Do not remove the microprocessor from the ACCUBAR
®
for any
reason. If there is a problem with the processor, please notify Sutron Customer
Service at (703) 406-2800. Only factory-trained personnel with specialized tools
can remove the microprocessor without damaging the unit and the processor.
Also note that each microprocessor has been characterized for the specific unit in
which it is placed; THEY ARE NOT INTERCHANGEABLE.
Additional Troubleshooting commands
Measure Break detect time
The SDI-12 specification requires that all sensors ignore breaks less than 6.5mS and states that they must
detect breaks that are at least 12mS in length. There is an RS-232 command for the unit to measure its
break detect time. The unit should be completely disconnected from the SDI-12 bus and the command
issued via the RS-232 interface. Note: The unit will ignore this command if issued via SDI-12.
