User Manual

Medio L40 - User's Guide
40/56 Revision 2.3 July 2013
5.3.1 Notion of read modes
During asynchronous read (or default read), the reader continuously tries to read all tags in the RF
field. Several options can be applied that modify the reader’s behavior during asynchronous read:
• “Multiplexer”: If this mode is active, the reader uses the multiplexer instead of the default
RF configuration for reading. The multiplexer makes it possible to define a sequence of
antennas, tag types and RF output powers that will be automatically used during the
reading process. For example, a user can configure the multiplexer so that reader tries to
read ISO15693 tags for 100ms on channel 1 at 1Watt, then ICode UID tags for 50ms on
channel 1 at 2Watts, then ISO15693 tags for 100ms on channel 2 at 1Watt, then ICode UID
tags for 50ms on channel 2 at 2Watts.
• “Input triggered”: If this mode is active, the reader waits for GPIO Input #1 to become active
in order to activate the RF field and start reading. When GPIO Input #1 gets back to
inactive state, RF field is turned off and the reader stops reading until input is active again.
Active input level (low or high) is software configurable.
• “Output feedback”: If this mode is active, the reader uses GPIO Outputs #2 to signal
reading activity. GPIO Output #2 is activated when the reader “sees” tags in the RF field.
The time an output remains active after the corresponding event has occurred is software
configurable.
• “Single”: If this mode is active, the reader will only scan once the current RF configuration.
Not applicable in non-multiplexer mode with C210 and C220 tags.
A user can activate one or several read modes at once, depending on the application
requirements.
5.3.2 Notion of events
During asynchronous read (or default read), the reader continuously tries to read all tags in the RF
field. When a tag is detected, one or several events are pushed into an internal event buffer. Those
events contain information such as the kind of event (see below), a timestamp, the channel on
which the event occurred, the tag type and the associated tag data (UID, memory…). The following
events are supported:
• “Tag Read”: This event is pushed each time a valid tag frame is decoded, without further
processing. When activated, this event may be triggered several hundreds of times per
second and is consequently bandwidth consuming. It is often used for testing purpose only.
• “Tag New”: This event is pushed each time a new tag is detected. If the same tag is
detected several times, it will be reported only once.
• “Tag In”: This event is pushed each time a tag enters the RF field.
• “Tag Out”: This event is pushed each time a tag leaves the RF field.
• “Tag No Read”: When Input triggered read mode is active, this event is pushed when the
trigger condition ends and no tag was detected in the RF field. When Input triggered read
mode is inactive, this event is never pushed.
A user can register for one or several events at once, depending on the application requirements.
For example, if a user registers for all events and a tag enters the RF field, stays in the field for
some time, and then leaves the field, the sequence of events pushed into the event buffer will be: