Alien Technology ALR-8780, Interface Manual

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C
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UNDAMENTALS
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EADER
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NTERFACE
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UIDE
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ONTROL
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that there are no more names to be heard, you move on to the letter ‘B’ and
repeat the series. By the time you’ve been through the letter ‘Z’, you should have
been able to get everyone’s name, and everyone should be sitting down. At this
point the sort has been finished.
Obviously this sort algorithm is far more complex than the global scroll algorithm,
requiring many more reader-tag instructions. However the Alien RFID Reader
considerably optimizes this basic sort method, and in doing so still provides a
very fast and efficient sort algorithm.
Acquire Parameters
When the reader scans for tags, it can automatically perform a complex
sequence of repeated wakes, sleeps, and reads. This sequence is defined by the
acquire parameters, and by adjusting each value you can configure the Reader
to perform optimally, depending on the particular use case.
When the reader does an acquire action, it performs a total number of acquire
cycles specified by the
AcqCycles parameter. Each cycle consists of a number
of Wakes (given by AcqEnterWakeCount ) on each antenna, then a number
of reads (given by AcqCount ) and Sleeps (given by AcqSleepCount ) on
each antenna. Finally, after all of the cycles have completed, a number of Wakes
(given by
AcqExitWakeCount ) are issued on each antenna.
The Wakes and Acquires all act on the current Tag Mask. The Sleeps act only on
tags as they are found.
The acquire parameters are demonstrated by the following pseudo-code:
foreach cycle in AcqCycles
foreach wake in AcqEnterWakeCount
foreach antenna in AntennaSequence
Wake (using current mask)
next antenna
next wake
foreach count in AcqCount
foreach antenna in AntennaSequence
DoAcquisition (using currentMask)
foreach sleep in AcqSleepCount
Sleep(TagsFound)
next sleep
next antenna
next count
next cycle
foreach wake in AcqExitWakeCount
foreach antenna in AntennaSequence
Wake(currentMask)
next antenna
next wake
Masks and Tag Memory Structure
Many commands aimed at Alien RFID tags require the setting of a mask, which
directs the commands only at the tags who's ID matches the mask. This