Hong Kong RFID has just completed a massive implementation
of passive RFID tags for Hong Kong Housing Authority. It is the largest RFID
implementation for asset management ever in HK in terms of no. of estates and
building services equipment involved; over 34000 pieces of tags were installed
in over 1700 buildings and over 300 estates. The project is aimed to keep track
of the equipment history of order and maintenance contracts. There are 67 types
of building service equipment can now be identified using RFID handhelds.
This 10-month project is completed within the schedule and
budget, and with an amazingly low defect rate. With this perfect
implementation, the Project Manager, Mr. Francis Tai, is thankful to his
assistant Mr. Ma Chun Man, the installation field operators and related IT
staffs for their excellent performance.
At the meantime, Mr. Francis Tai would like to share his
experience and his tips for such as successful implementation, for those who
might be planning to install similar projects.
Design considerations and tips for RFID tagging for asset
management projects:
1)
The ID written in RFID Tag, the memory block designation
It is important to have a good plan on how to write the information.
Here are the basics of RFID; inside each RFID tag, there are memory storages divided
similar to different document trays on your table; the up-most tray is called
EPC, which is the part RFID readers read first and distinct the tags by the ID.
The second tray is the User memory, which the information are storage. The third
and fourth tray are where lock and kill password stored. They acts like the
keys for write-protection and kill-protection. Many RFID IC manufacturers have different
sizes on EPC and User memory range from 96-bit to 512-bit, the lock/kill password
are generally 32-bit. Some models may have the last tray called TID, a unique
ID managed by IC manufacturer, either 32-bit or 64-bit.
It is important to consider who will manage the ID sequence; the user, the
equipment provider, the tag provider, the tag writer or the integrator. And which
format is used; there are widely recognized standards such as GIAI-96 or GIAI-128
for reference. A password or lock and kill can increase the robustness of such
systems, which might be used by multiple parties.
2)
Sensitive mount-on-metal RFID tag,
The better sensitivity is, the longer is the reading range. It is affected
by the size of tag, the antenna type of reader and the power of RFID reader.
Except the last one can be adjusted through reader software, others are parameters
set once the tag and reader models are confirmed. It is recommended to select a
tag and reader model which exceed the actual operation requirements by 50-100%.
For example, choose the tag which can read 1-2m even though less than 1m is
required.
3)
Continuity of RFID tag IC, readers and standards
For asset management which the system commonly operates more than 5-10
years, it is important to consider the continuity of RFID tag IC models and readers.
Special features for some models might seem useful at first but it might be a
big trouble once the IC or readers discontinued, or no longer supported.
4)
Tagging objects and mounting methods
The equipment to be tagged have many kinds of surface, such as metal,
concrete, plastic, wood and fiber board. The RFID tag should work on these
surfaces. Generally, concrete wall surfaces reduce the reading range by up to 10-20%.
Metal object behind the RFID tag will not affect the tag but those hinder the
line-of-sight would reduce the range substantially.
As a result, the mounting methods for all kinds of equipment should be
well defined to avoid the situations described, leading to bad reading range.
5)
Visual information is as important as invisible information
Even though RFID provides computer-recognized information, it is still a
good idea to print clear human recognizable information on the tag using label.
Not just reducing errors in installation, it also makes a lot easier for operators
to spot the tag. Hence, the printing machine and printing label software should
be part of the system design in the project.
6)
Multiple reading sometimes getting problematic
One of the key feature of RFID to out-perform barcode is the ability to
scan multiple tags. However, the system providers should be careful of doing
single tag operations when other tags are in range. For example, reading/writing
one specific tag information in between 4-5pcs of tags which installed nearby. Tragedy
happens if the system provider overlooks this and roll out the system. Enough tests
should be done to prove the software’s robustness. There are many tips to avoid
such thing happens but the technical contents are beyond the scope of this article.
Please feel free to consult your RFID solution providers.
Lastly, it is highly recommended to hire a qualified RFID integrator who have prior experience rather than relying on in-house IT team. Here are some tips for system
integrators on how to achieve ZERO Failure in Passive RFID
Installation for Asset Management.
1)
Well-planned installation method for various types of Building Service equipment
It is a must to try all the RFID on all types of building service
equipment in real situations. There are lots of RF-unfriendly environment or physical installation restriction which may be out of the plan. Earlier spotting on these situations can have earlier communication with client, so as to manage their expectation.
2)
Well-QC and well-written RFID tag before RFID installation
It is highly recommended to prepare the tag in controllable environment
like factory or office, rather than on-site. All tag information, written data
and printed information are recommended to store in database.
3)
Well-programmed RFID Handheld during Installation
During installation, the RFID handheld are recommended to load with program
only designed for installation. Tests should be included during installation, such
as reading range test, ID and information check. The operation log/record should
be kept and synchronized once back to office.
Please contact us if you have any question or suggestions.
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