INfinity 510 Protocol Reference Guide - Sirit

Chapter 4 – Reader Behavior
A tag id matches the filter if the important bits (as specified by a ‘1’ in
the mask) of the pattern match the same bits in the tag id. Each of
the filters is specified to be either ‘inclusive’ = true, meaning that only
tags matching the filter are reported, or ‘inclusive’ = false (or
exclusive), meaning that tags not matching the filter are reported.
This can be described with the following algorithm:
if ((tag.filter.n.pattern & tag.filter.n.mask) ==
(tag_id & tag.filter.n.mask))
{
// tag id matches the pattern with the mask.
if (tag.filter.n.inclusive == true)
{
// report tag
}
}
else
{
// tag id does NOT matches the pattern with the
mask.
if (tag.filter.n.inclusive == false)
{
// report tag
}
}
Using Multiple Filters
Multiple filters can be specified. Each of the filters is specified to be either
inclusive meaning that only tags matching the filter are reported, or
exclusive, meaning that tags not matching the filter are reported. If multiple
filters are used, a tag is reported only if the following two conditions hold:
The tag matches at least one of the inclusive filters and
The tag does not match any of the exclusive filters.
There is a special case, if no inclusive patterns are defined, the first check
is omitted.
Example Filter Usage
This section presents the filter setting to configure a reader to only report
SGTIN-96 tags with a filter value indicating a Single Shipping/ Consumer
Trade Item.
SGTIN-96 tags are identified with an 8-bit header value of 0011 0000
(binary) or 0x30 (hex). The next 3 bits of an SGTIN-96 tag are the
filter value. The filter value is additional data that is used for fast
filtering and pre-selection of basic logistics types.
34 INfinity 510 Protocol Reference Guide