User's Manual

USER MANUAL – ActivDuo Active RFID Tags
Configuration No. Wavetrend Technologies Ltd Master File Name Issue Date Page
00000-0000-150-1 User Manual ActivDuo Tag-00.8-UM-LT 3 DECEMBER 2008 13 OF 42
While the tag batteries are manufactured on demand for Wavetrend to minimize the loss of functional life
span between battery manufacture and customer activation of the tag, Wavetrend typically quotes a
conservative maximum battery life span of 6 years 2 months for tags set to the default transmission rates to
allow for a more than reasonable amount of time that the tag might be stored in stock by our distributors &
resellers and to allow for usage in either variable temperature or colder climates.
While hotter temperatures will decrease the transmission interval rates, thus making the tag transmit more
often per day, the greater efficiency of the battery exceeds the increased power usage caused by the shorter
transmission interval. In reverse, the loss of battery efficiency at colder temperatures exceeds the benefit of
longer actual transmission intervals.
We feel it is better to be conservative than to set expectations that may lead to customer disappointment, but
for the majority of tags sold we would expect the customer to enjoy a potential maximum life span of up to
between 7 and 8 years from a tag – depending very much on how the tag is configured to operate, how much
data is transmitted per transmission (W-Series tags only), and the ambient temperature it will experience
throughout its life span.
Summary: What can reduce a tag’s life span?
Transmission intervals. Shorter standard and alert intervals = shorter life span.
Ambient temperatures. The power consumption of the electrical components inside the tag will
change very slightly with changes in temperature and the battery will be less efficient in generating
energy.
Colder temperatures = shorter life span.
Regular temperature cycles. Where the tag is subjected to repeated and regular temperature cycles (hot /
cold / hot etc.) the battery life span will be reduced. The greater the extremes in hot and cold, the greater the
reduction of life span.
Regular temperature cycles = shorter life span.
The amount of movement, and therefore how often the Alert mode is initiated, will affect life span.
More movement = shorter life span.
The amount of data the tag transmits. L-Series tags transmit a fixed amount of data and life span calculations
are quite straightforward. W-Series tags can transmit anything between 8 & 28 bytes of data, and this
variable amount of data, and thus variable transmission duration lengths, makes life span calculations more
complex.
More data = shorter life span
1.5.1 L-Series Life Spans
The L-Series ActivDuo tag will typically give the user greater than 6 years 2 months of continuous use when
set to transmit at its default Status Tx rate of 10 seconds.
The tag will give the user just under 5 years of continuous use even if it is exposed to movement of up to
90% of its total functional life span when the Alert Tx rate is set to the default rate of 1.5 seconds.
For other Alert Tx rates less than 1.5 seconds, and where the tag moves for more than 10% of its total
functional life span, the tag battery life span will be reduced, due to the greater number of transmissions
initiated during its life span.
At worst the tag will offer a user just under 2 years of continuous use when set to the shortest Alert Tx rate
(0.4s) and when it moves for up to 90% of its functional life span.