Specifications

HYDROLOGICAL SERVICES
DL3 100-039 IMP
Issue 2: 15/11/2005
Power Supply 6V to 14V DC unregulated.
75mA operating mode 200uA sleep mode.
Transient Protection Each input protected to 500V DC
at 20 Joules w.r.t 0V.
PCB Dimensions 2.8 x4
RRDL-3 Box Dimensions 4.7 x3 x2.7
Weight Less than 1 lb (Including internal batteries)
Help Unique on board help system to give available commands as
well as individual command description and syntax.
5.1.2 Rainfall Sensor Interface
The standard RRDL-3 logger includes a digital tipping bucket rain gauge (TBRG) interface. The
occurrence of a user defined rainfall event causes the logger to wake momentarily, record the
event to the historical record, transmit the event on the serial port (if the EV flag is on), update
the rainfall since 09:00 and check for the 3 types of rainfall alarm before going back to sleep.
5.1.3 River Height Sensor Interface
The standard RRDL-3 logger includes a digital river height interface for connection to a
quadrature shaft encoder. A separate analog interface has been developed for connection with
pressure transducers and other 4 to 20 mA sensing equipment. The complete interface will be
contained in the same box as the standard RRDL-3 unit with all connections made via the sensor
connector port. The standard RRDL-3 software load supports 4 to 20 mA sensing with specific
set-up parameters included to configure an analog system.
In a digital river system (shaft encoder), the occurrence of a user defined river height event causes
the logger to wake momentarily and record the event to the historical record, transmit the event
on the serial port (if the EV flag is on), check for river peak, update river trends, check for the 3
type of river alarm before going back to sleep. In an analog system, the sensing device requires
power to operate, therefore, to theoretically capture every event, the sensing unit would require
continuous power. Since this is not practical due to power requirements, a quasi event recording
mechanism for analog recording has been implemented. The logger wakes every minute to power
the sensing device, allow for settling time, take a measurement and return to sleep mode. If the
measurement is different from the last logged value by more than the defined river increment, then
the new measurement is logged.