MJK Automation Shuttle Ultrasonic Level Transmitter and Sensor - Manual (Page 32)

32 GB Shuttle Manual 100316 SW 838023
Fault finding
Fault finding
General
Almost all system errors are due to the echo from the ultrasonic sensor being either too weak
or missing. This is normally caused by incorrect installation of the ultrasonic sensor, a faulty
ultrasonic sensor or by faults on the cable between the ultrasonic sensor and the Shuttle
®
level meter. Other factors also have an influence on the ultrasonic level measurement. But
always check first that the ultrasonic sensor is installed correctly and is working properly. See
also the fault finding table on the facing page.
Indications on system errors
First, Shuttle
® will indicate that the echo is too weak or missing. After 5 minutes Shuttle ® dis-
plays 'S.Err', and if one of the relays is set to be activated on a system error, the relay will be
activated after the delay time. At the same time the signal from the mA output will be either
locked on the last known value or provide a preset signal value (3.5 - 20.5 mA). Other valid
error types are temperature errors, internal stack errors and EE-PROM errors (see below).
If the problem disappears, Shuttle
® will change back to normal read-out. At the same mo-
ment, the relay output set as alarm output will switch back to its normal position and the mA
output will provide a normal signal.
System (sensor) error
If echo is still weak after 5
minutes, Shuttle
® enters
system error mode and
sends an alarm. Also, relays
configured for pump control
will be deactivated.
Too weak or missing echo
The received echo is too
weak for Shuttle
® to per-
form a safe and reliable level
measurement.
Normal read-out
Shuttle
® receives an echo
that has sufficient strength
for a safe and reliable level
measurement.
Temperature error
Contack an MJK service
representative, if a tempera-
ture error appers.
Internal stack error
Contack an MJK service
representative, if an internal
stack error appers.