ThingMagic Mercury API v1.23.0 - Manual (Page 27)

Reading Tags - The Basics
Level 1 API 27
Note
The C# version of this API uses the native delegate/event mechanism with
delegates called
TagReadHandler and ReadExceptionHandler and
events named TagRead and ReadException, rather than the Java-style
listener mechanism.
Pseudo-Asynchronous Reading
In pseudo-asynchronous reading a synchronous search is looped over and over again
running indefinitely in a separate thread. Tags are off-loaded once every synchronous
search is completed. i.e., read listeners will be called once for every “/reader/read/
asyncOnTime” milliseconds. On all readers except the M6, M6e and Micro pseudo-
asynchronous reading is the only implementation used for background reading
operations.
Continuous Reading
The M6, M6e and Micro also support true continuous reading which allows for 100% read
duty cycle - with the exception of brief pauses during RF frequency hops. Continuous
reading is enabled when
/reader/read/asyncOffTime is set to zero. In this mode tags are
streamed to the host processor as they are read.
Note
In continuous mode there is currently no on-reader de-duplication, every tag
read will result in a tagread event being raised. This can result in a lot of
communication and tag handling overhead which the host processor must
be able to handle it. Consider the details on setting Gen2 Session and
Target values, as described in
How UHF RFID Works (Gen2) , to decrease the
frequency of tag replies to inventory operations as a way to decrease traffic.
Return on N Tags Found
In addition to reading for the specified timeout or asyncOnTime period and returning all
the tags found during that period, it is also possible to return immediately (more
specifically, the time granularity is one Gen2 inventory round) upon reading a specified
number of tags.
The behavior is invoked by creating a StopTriggerReadPlan with the desired number of
tags and setting it as the active /reader/read/plan .
For optimum performance it is recommended to use a StaticQ setting for /reader/gen2/q
appropriate for the specified value of N, where: