User Manual

Tag Read Meta Data
Functionality of the Mercury6e 47
Tag Read Meta Data
In addition to the tag EPC ID resulting from M6e inventory operation each TagReadData
(see MercuryAPI for code details) contains meta data about how, where and when the tag
was read. The specific meta data available for each tag read is as follows:
Tag Read Meta Data
Meta Data Field Description
Antenna ID The antenna on with the tag was read. If the same tag is read
on more than one antenna there will be a tag buffer entry for
each antenna on which the tag was read. When
Using a Multi-
plexer, if appropriately configured, the Antenna ID entry will
contain the logical antenna port of the tag read.
Read Count The number of times the tag was read on [Antenna ID].
Timestamp The time the tag was read, relative to the time the command to
read was issued, in milliseconds. If the Tag Read Meta Data is
not retrieved from the Tag Buffer between read commands
there will be no way to distinguish order of tags read with dif-
ferent read command invocations.
Tag Data When reading an embedded TagOp is specified for a Read-
Plan the TagReadData will contain the first 4 bytes of data
returned for each tag.
Note: Tags with the same TagID but different Tag Data
can be considered unique and each get a Tag
Buffer entry if set in the reader configuration
parameter /reader/tagReadData/
uniqueByData. By default it is not.
Frequency The frequency on which the tag was read
Tag Phase Average phase of tag response in degrees
LQI/RSSI The receive signal strength of the tag response in dBm.
GPIO Status The signal status (High or Low) of all GPIO pins when tag was
read.