User's Manual

Speed Tx User Manual
Miltel Communications Ltd. 7
2.2.2 Digital Section
The digital section of the Speed Tx performs the following functions:
 Samples reed switches to detect short/open from each meter.
 Accumulates number of pulses for each meter separately
 Stores data (including battery and tamper alarms) and stores information
internal memory
 Interfaces the data to the RF section
The digital section is based on a central controller which accepts the following inputs:
a. Analog inputs (from reed-relay contacts) designated INPUT1 through INPUTn,
each indicating the advance of a single water meter. These are the only inputs
of the controller which are connected to the external source.
b. Magnetic switch input is utilized only for test.
c. The TAMPER SWITCH input is connected to a micro-switch that senses an
opening of the unit's box. This enables the Speed Tx to generate and transmit
an alarm signal in the event of unauthorized opening of the unit casing.
d. The LOW VOLTAGE input of the controller is connected to battery via a Low
Voltage Detector in order to sense and generate a low battery alarm.
Each of the external analog inputs to the controller advances a separate counter in
singular steps. The counters in the controller are not pre-settable or resettable to
avoid unauthorized tampering (counter matching is thus performed only by the central
computer, ensuring excellent data security at the sites).