Avery Dennison RFID - Manual (Page 20)

HowToRFID
Revision: 13 Date: 31 August 2009
Page 20 of 53
3 Prepare the printer
3.1 Configuration
3.1.1 Activating the RFID-option
The very first thing to do for using RFID in an AVERY printer is to activate the RFID option. To activate RFID set
parameter „Interface Parameter / OPTIONS / RFID Option“ to the value of appropriate COM interface (internal
serial RS232 interface). After confirming the entry the printer reboots itself with appropriate settings for internal use
of COM.
Printer type RFID option (internal connection)
AP 5.4 (Marlin CPU board) Serial Com3
AP 5.4 (Redfin CPU board / Marlin MLK) Serial Com4
64 series / DPM / ALX 92x (Gen 2 CPU board) Serial Com2
64 series “High Performance” / DPM / ALX 92x (Gen 3 /
Dolphin CPU board) Serial Com4
Table 7 – Serial port for RFID option
3.1.2 Material depending RFID parameters
3.1.2.1 Power level
The Power level setting is a very critical part of the whole setup of an RFID printer. The Power level setting controls
the output power of the radio module of the RFID reader. The output power must be adjusted an a way that the
inlay to be processed (in direct coupling with the antenna) gets enough “radio” energy to be able to respond to the
request from the RFID reader – but on the other side to avoid the activation of adjacent tags (resulting in unwanted
reads or writes from multiple transponders).
To find the right setting can be a tricky and time consuming process. It depends mainly from the dimensions of the
material especially the pitch between inlays and the type of inlay used.
To ease this process Avery Dennison has introduced a RFID inlay qualification process, were popular transponders
/ inlays get tested in the lab. See section 4.2 for details.
There is a simple rule of thumb: adjust to the lowest power level which gives constant success. Applying to much
power leads to problems caused by reflections and adjacent reads/writes.
Please note: the RF transmit power depends from the built-in RFID reader module, which is a different one for the
different regulatory regions (EU/ETSI, US/FCC, Korea).
Power control changing an “attenuation” value
Up to and including printer firmware versions Vx.33, the power level is adjusted by a numerical value which controls
the attenuation of the transmitted radio signal. Resultant in reverse logic: high numerical value => low power, low
numerical value => high power. The output power doesn’t follow a linear curve, especially in the range of 255 –
200. Therefore changes in small steps may result in very large differences in read / write success.
In most technical documents radio output power is measured in the unit of the physical power level mili watts (mW)
and is presented as logarithmic scaled value in dBm.