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the Controller and all Power Supply Units. If a wireless sensor network is in use,
investigate possible impediments to network communications.
10.2.5.
Wiper Stalled Message
A Wiper Stalled message will appear if the wiper does not operate when expected
or if rotation of the wiper blade is not detected. It may also indicate drag on the
wiper motor as a result of debris being attached to the wiper blade or shaft. Visually
inspect the sensor to determine that the wiper blade and shaft are free of debris.
Verify that the wiper is securely connected to the wiper shaft and that it turns freely
(1-3 revolutions) when power is cycled to the sensor or the Wiper Timing parameter
is changed. Replace the wiper blade, as indicated in Section 9.3.1.
10.2.6.
Wiper Motor Failure
Message
This message indicates an internal electronic failure of the wiper motor. Contact
Entech Design for repair or replacement options.
Note: Wiper motor failure may cause unreliable measurements.
10.2.7.
4-20 mA
Measurement Discrepancy
EchoSmart 4-20 mA devices are active (powered) and isolated current loops. Check
that no other power or isolation is present on the loop, and confirm that no other
electronic devices or electrical elements intervene on the current loop. Check that
appropriate signal cable is in use.
EchoSmart allows the user to span the 4-20 mA signal with reference to Level
(depth of sludge) or Range (distance from water surface to top of sludge). Confirm
that the correct parameter has been entered.
The maximum span is 0.0 to Tank Depth. The 4mA Set Point and 20mA Set Point
must be correctly entered to establish the desired span. Check that corresponding
Set Point values are entered in the customer data acquisition system.
Disconnect loop cables from the EchoSmart equipment and measure the current
output to determine whether it corresponds with the measurement indication from
the instrument.
10.2.8.
Sensors Not Detected and No Sensors Found Message
If sensors are not detected or a
No Sensors Found
message is reported, confirm that
all sensor and communication cables are securely landed at the respective
Controller or Power Supply Unit(s) and that main power is ON.
If a Controller operates more than one sensor, confirm that all sensors have been
added to the Network as directed in
13.2. Configuring a Sensor Network
, and that
each has a unique address designation. If multiple sensors have the same address
number, the Controller will not be able to establish communication with those
