
SapIP – IRT Instruction Manual 1/23/2017
Page 25
Dynamax, Inc.
IV.
Sequential and Functional Descriptions
1.
Initialize
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After resetting the hardware, all of the digital hardware is initialized to a known state that will be
ready for use.
1.1
Charge Battery Begins
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First an EEPROM variable is monitored by the processor to indicate a thermistor is embedded in
the battery pack. When the command is given to top-off charge ( see 9.1 for IRT_ZB or 8 for
IRT_SDI) the rapid high current charge sequence begins until termination. If the thermistor is not
present then the unit will ignore temperature and stay in top-off mode until it reaches 6.2 V or
charges for 5 hours (whichever occurs first). If the thermistor is present, termination can also occur
if the battery exceeds maximum temperature, goes below minimum or the temperature rises too
rapidly.
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All currents are set at 12 V input to the external battery charger circuit (solar panel input).
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The source of the units charge is from the solar panel (see specs).
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Charging is discontinued momentarily during the noise sensitive measurement cycle (2 seconds).
1.2
Check Battery Voltage
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Battery voltage is checked to see if it is in the acceptable range. If the battery is below 3.8 V a very
slow LED blink will begin. The LED will be on for 10 milliseconds and off for 10 seconds and the
charger will continue to function if it can.
-
The IRT unit is frozen in this routine and will not change until the voltage rises over 4.2 volts.
1.3
Start Radio Link
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Zigbee radio will then be turned on. The radio will attempt to join a network on PAN 100. The
radio is then put to sleep.
o
Note: Joining attempts will continue based on the unit’s profile settings.
-
Radios are programmed for API mode. End device destination is set for 0= coordinator, PAN=100,
sleep mode=pin hibernate.
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Coordinator is set for PAN100, child poll timeout set to 30 minutes.
2.
Read Temperature
-
The Melaxis IR temperature sensor is read through an I2c two wire port. Six samples are taken 10
seconds apart, averaged and stored in an accumulator (Note: 6 x 10 seconds = 1 minute.). If the
EEPROM interval is set to zero, only one sample is taken.
3.
Timing and Sleep Considerations
-
Sampling takes 2 seconds.