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The Often-Overlooked Enclosure
One of the often-overlooked accessories required for a RFID solution are equipment enclosures. Many never think about this issue until after the initial installation. Not surprisingly, managers are focused on tags, readers, software, and multitudes of other minutiae and neglect to consider how equipment will be physically incorporated into their operations. Depending on the set-up, choosing the right enclosure may be as important as selecting the appropriate tags and readers.
What should you look for when shopping for equipment enclosures? There are a number of important considerations:
- What are the physical installation requirements?
- Is the enclosure flexible enough to hold equipment in the position required for optimal performance?
- Will the enclosure protect the equipment from the dangers of everyday operation?
- What’s it going to cost?
There can be some pretty scary RFID installations: antennaes mounted on plywood, readers screwed into concrete above dock doors, exposed wires, and the list goes on. The antenna is simply clamped to a bollard next to a dock door. There is no protection for the antenna; a simple bump will cause the antenna placement to move which will adversely affect read performance, plus the wires connecting it to the reader are exposed. This is a good example of what not to do.
What are the physical installation requirements?
The first consideration is: what equipment does it need to hold? Will it house just a single antenna, or a complete outfit including multiple antennaes, reader, uninterruptible power supply (UPS), program logic controllers (PLC) and wiring? Be sure to carefully calculate dimensions, volume, and weight requirements.
Consider the location where the equipment is to be installed. Will the enclosure be sitting on the concrete floor, or be mounted to the wall or even the ceiling? If it’s a portal, such as a doorway, will the enclosure protrude into the walkway? In this case, can the enclosure be recessed into the wall? Will the mounting location support the weight for all equipment plus the enclosure weight or is additional structural support needed?
Are there physical appearance requirements? An equipment enclosure for a retail sales floor will undoubtedly have aesthetic requirements not necessary for a stock room. Corporate colors and logos may need to be added.
Does the unit have cable channels and conduits large enough to accommodate all of the wires?
Can it support light indicators, motion sensors, photo-eyes, UPS, PLC, and other accessories that may be needed?
Can one person install the enclosure or does it require multiple people? If you are installing hundreds or even thousands of read points, the time and effort required may be enormous. Some enclosures are so bulky that two strong individuals are needed just to lift them. This can quickly double labor costs.
What tools are needed? Special screws require special screw drivers. Try to avoid having to bring a big tool box to the installation location. Some enclosures on the market today are tool-less, and use thumbscrews or snap-to-fit components.
How easy is the unit to service once it’s installed? How fast can a reader, antenna, or accessory be replaced?
Is the enclosure flexible enough to hold equipment in the position required for optimal performance?
A lot of time and effort can go into the design of a read point. Engineers may determine that antennaes should be at a specific height and particular angles. If the enclosure cannot accommodate the optimal equipment position, then system performance will ultimately suffer.
Antenna mounts should have adjustable height and angle positions. You may need the ability to ‘cant’ the antennas, especially at dock door read points. Refer to the picture on the left. You’ll note that the upper antenna is ‘canted’ down while the lower antenna is at a 90° angle to the floor. The read point may also need to have the antenna angled towards or away from the dock door.
Enclosures should be equipment agnostic. In two years, what if a decision is made to replace your current readers and/or antennaes with a new model or one from a different manufacturer? Will you have to replace your enclosures as well?
Will it protect the equipment from the dangers of everyday operation?
Finally, and most importantly, the enclosure must protect the equipment.
What are the environmental conditions? When building an exterior portal, such as a dock door, consider the elements that may come through the door. Will rain and/or snow be coming through the door?
What are the temperature and humidity extremes? Will the equipment require cooling in extremely hot locations or de-humidifying in refrigerator or freezer environments?
Will the enclosure keep out the muck? There will always be dirt and dust, but in industrial environments you’ll also find grease and occasionally even filings from manufacturing machinery (wood, metal, etc.).
The ‘Furniture’ factor. In your average warehouse or industrial installation, it is not unusual to see a dock door portal, or other conveniently located reader, become a well-used table for coffee cups or pizza plates. Keep in mind enclosures may be used as a coat rack, a shelf for magazines and flyers, a leaning post, or serve numerous other functions you would never imagine.
They will also get kicked, banged, bumped, and slammed; often by accident, but occasionally on purpose. Which leads to the next point …
Are there security requirements? Is a lock on the enclosure necessary to prevent unauthorized access or prevent tampering? Always educate staff regarding RFID technology so they aren’t concerned their jobs are at risk because of the new technology. Be sure to tell everyone the equipment is not meant to track them, unless it is.
Bollards are a requirement. The results of a forklift impact on an RFID enclosure are not pretty. There are no enclosures on the market that can withstand a direct hit. If there were, it would be too heavy and too expensive. It is important that bollards (the yellow cement poles) or a bumper are installed to protect your enclosure.
What composite materials are best? Equipment enclosures may be constructed of metal, such as extruded aluminum and steel, plastic, wood, fiberglass, Lexan, or combinations of the above. For larger enclosures, consider extruded aluminum. This is the same material that secures windows in place on skyscrapers. Compared to steel, it is lighter, easier to modify, less expensive, and not prone to rust. Metal also reflects RF, which in many installations is an advantage due to its ability to help isolate adjacent read points.
What’s it going to cost?
Enclosures such as the dock door solution (pictured above and right) start at around $1,500 each with no equipment. Here’s an example of the cost for a complete solution to support three dock doors:
- Gen 2 certified readers
- Bi-static antennas
- Software for reader coordination
Adding a Lexan facing is around $250 per enclosure. Other options such as light stacks, photo eyes, and motion sensors also add cost.
Also factor for:
- Labor for installation
- Industrial gauge wire cover for power and network running to the enclosure
- Shipping and taxes
Finally, when considering shipping costs, a heavy steel unit may cost hundreds of dollars more to ship than a lighter weight extruded aluminum or plastic unit.
Hopefully, we’ve helped point out the most obvious reasons why enclosures are an important part of your RFID solution. Happy shopping.