Setup Guide

"P" – PROTOCOL control (Gen2 Air protocol)
"P" – PROTOCOL control (Gen2 Air protocol)
P[<TARI><MODE><LF>]
<TARI> = 0..2
<MODE> = 0..3
<LF> = 0..4
The reader supports a number of different data rates and modulation modes for
communicating with Gen2 RFID tags. This functionality is controlled by the P command.
Read performance is closely tied to how the various modulation, tag signaling and data rate
parameters interact in a particular use case. Changes away from recommended settings should
be done only after sufficient testing demonstrates an improvement. The best settings are often
a compromise between read speed and read reliability. In some cases it may be beneficial to
change this setting to improve performance in multi-reader environments.
Each of the <TARI>, <MODE>, and <LF> parameters can take on a simple integer value,
corresponding to one of the available settings for that parameter, as outlined in the following
table.
Available Parameters
Value TARI Modulation Mode
(MODE)
Link Frequency
(LF)
0
6.25 uSec FM0 40KHz
1
12.5 uSec M2 160 kHz
2
25 uSec M4 256 kHz
3
- M8 320 kHz
4
- - 640 kHz
Recommended Settings
The default Protocol Control values from start up or a (PR – reset) command correspond to a
setting of “231”, or a 25uSec TARI, M8, and a 160kHz LF. This is close to the DRM (Dense Reader
Mode) requirement defined be EPCglobal, and works well in most situations.
Normal Operation : P222
Dense Reader Environment: P231
High Speed Reads of Small Numbers of Tags: P112
38