RDD100 User Guide
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3
OPERATION
3.1
Start Up Messages
When the RDD100 is powered up, it goes through a test of its display segments and its error LED. The error LED
is located beneath the least significant digit of the display. All segments should light for a brief period and then
the display transitions to “rdd100”, “Sr 2.0”, and “rEAdY”. Note: older RDD100 units may not display “Sr 2.0”.
Newer RDD100 units may also have additional LED in the lower right hand corner of the display which flashes as
each packet of data is received.
If a transducer is properly set up and connected to the RDD100, pressure readings will appear on the display.
3.2
Error Indications
3.2.1
No Transducer Connected
If the RDD100 does not detect a transducer, the display will go through the segments and LED check, display
“rdd100”, display “Sr 2.0”, and finally display “rEAdY” before going dark with only the error LED illuminated. Note:
older RDD100 units may not display “Sr 2.0”.
3.2.2
Incorrect Baud Rate
If the RDD100 sees a transducer, set to the wrong baud rate, the display will go through the segments and LED
check,
display “rdd100”, display “Sr 2.0”, display “rEAdY” and then hold with the “rEAdY” message. Note: older
RDD100 units may not display “Sr 2.0”.
3.2.3
Not Set Up To Continuously Transmit
If the RDD100 sees a transducer that has not been set up to continuously transmit, the display will go through the
segments and LED check,
display “rdd100”, display “Sr 2.0” and finally display “rEAdY” before going dark with
only the error LED illuminated. Note: older RDD100 units may not display “Sr 2.0”.
3.2.4
Wrong Polarity Of DC Power
The RDD100 is equipped with the reverse polarity protection diodes at its power input. The instrument will
operate with either polarity.
3.2.5
Transducer Disconnected While Transmitting
If the transducer is disconnected while transmitting, the last reading received will remain on the display and the
error LED will light, indicating that no further updates are being made. Reestablishing connection to the
transducer will result in a continuation of reading updates and the error LED will turn off.
NOTE: the RDD100 may appear to be in this condition if the transducer has been programmed with a long
integration time or idle count yielding long durations between readings. If changed from its factory default
settings, it is recommended that the connected transducer be programmed to provide 1 or more readings per
second to prevent this possible confusion. (The typical factory default reading rate is 5/second.)
3.2.6
Over/Under-Ranged Transducer Indications
In the event that a transducer, experiencing an applied pressure or temperature which is over or under the
specified range, is connected to the RDD100, the LED display will flash on-off-on-
off…with the current readings to
indicate the over/under-ranged condition.
Over/under-ranged con
ditions on older RDD100’s (prior to Sr 2.0) will indicate the following:
Sequence #1:
If a transducer that is in an over/under ranged condition is connected to the RDD100 and then the power is
applied to the RDD100, the result will be a start-up message t
hat continuously displays “rEAdY”.
Sequence #2:
If the RDD100 is powered up and then an over/under ranged transducer is connected to the RDD100, the result
will be a blank display and the error LED will light.
Once the over/under range condition is removed, normal operation of the RDD100 will be restored.
