User's Manual
ElectroStatic Discharge (ESD) Considerations
A DIVISION OF TRIMBLE
116 Appendix C: Environmental Considerations
ElectroStatic Discharge (ESD) Considerations
WARNING!
The ThingMagic Nano antenna port may be susceptible to damage from
Electrostatic Discharge (ESD). Equipment failure can result if the antenna or
communication ports are subjected to ESD. Standard ESD precautions should
be taken during installation to avoid static discharge when handling or making
connections to the ThingMagic Nano reader antenna or communication ports.
Environmental analysis should also be performed to ensure static is not building
up on and around the antennas, possibly causing discharges during operation.
ESD Damage Overview
In ThingMagic Nano-based reader installations where readers have failed without known
cause, based on anecdotal information ESD has been found to be the most common
cause. Failures due to ESD tend to be in the ThingMagic Nano power amplifier section
(PA). PA failures typically manifest themselves at the software interface in the following
ways:
RF operations (read, write, etc.) respond with Assert - 7F01 - indicating a a fatal
error. This is typically due to the module not being able to reach the target power
level due to PA damage.
RF operations (read, write, etc.) respond with No Antenna Connected/Detected
even when a known good antenna is attached.
Unexpected Invalid Command errors, indicating command not supported, when that
command had worked just fine shortly before. The reason a command becomes
suddenly not supported is that the reader, in the course of its self protection routines,
has returned to the bootloader to prevent any further damage. This jump to boot
loader caused by power amp damage occurs at the start of any read tag commands.
Ultimately determining that ESD is the root cause of failures is difficult because it relies on
negative result experiments, i.e. it is the lack of failure after a configuration change, rather
than a positive flag wave that says “I’m ESD”. Such flag waves are sometimes, but only
sometimes, available at the un-packaged transistor level under high power microscopy.
The remoteness of microscopic examination from the installed field failures is indicative of
the high cost of using such analysis methods for chasing down ESD issues. Therefore