User Manual

Medio L40 - User's Guide

July 2013 2.3 39/56

to configure those interfaces for console or StxNG protocol operation: both are simultaneously

available.

For more information about serial console please refer to Medio L400/L40 Designer’s guide.

5.2.5 Standalone mode

Standalone mode makes it possible to use the reader without the need for a host to control it. In

this case, only the tag reading operation is available.

When standalone mode is activated, the reader automatically loads its last saved configuration

upon start-up and initiates a read session. Each time a read event occurs, the reader sends a

frame over both its serial and USB ports. Frame format is as the following (all fields are ASCII,

optional and customizable):

A watchdog can also be activated. In this case, a customizable frame is sent periodically over the

serial port to indicate the reader is operating properly.

For more information about standalone mode operation and configuration, please refer to Medio

L400/L40 Designer’s guide.

5.3 Reader operation principles

Most of the reader commands are executed in a synchronous manner. This means that the reader

waits for an incoming request from the host, executes the associated operation then sends a reply

containing operation execution status back to the host. Between the reception of two consecutive

commands, the reader does nothing but wait for the next command.

The following commands are examples of commands executed in a synchronous manner:

• Configuration commands (configuring the TCP/IP stack, for example).

• Tag writing commands (writing an ISO15693 tag memory block, for example).

• Most tag reading commands (reading the locking status of an ISO15693 tag memory block,

for example).

Synchronous commands that actually perform an operation on tags in the RF field (such as a

writing operation, opposed to a configuration command) can only use a single channel (multiplexer

can not be used). The channel and RF power that should be used for any subsequent synchronous

tag operation is called the default RF configuration (specific commands exist to get/set this

configuration).

An exception to the mechanism described above exists: the asynchronous read (or default read).

Asynchronous read (or default read) can be activated or deactivated using the appropriate

commands in the command set. During asynchronous read, the reader continuously tries to read

all tags in the field. When a tag is detected, one or several read events are asynchronously pushed

into an internal buffer (the event buffer). The host system then needs to poll the event buffer

periodically to retrieve the latest events.

One can specify the kind of read events that should be reported during asynchronous read, as well

as several options (called read modes) that should be applied during asynchronous read. The

following sections provide more details about the different read events, as well as the different read

modes.