During our recent webinar "Dispelling the Myths about Active RFID," held jointly with IAITAM, there were an unusually large number of questions. Because of time limitations, we were unable to answer all of them. As promised, here is a list of the questions and answers not heard during the webinar.
Q: What is the general cost for readers - both enterprise wide, room and rack types?
A: Area or zonal readers have a list price of $1249.00 and rack readers have a list price of $595.00 (USD).
Q: What is the effective range (feet or yards) of active RF tags?
A: Typically RF Code tags can effectively work at 300 feet. Under optimal circumstances it could be more.
Q: How is it possible to relate an active tag to a physical location such as individual cubicles in a large office environment with hundreds of cubicles per floor, multiple floors, and multiple buildings?
A: Individual office and cube resolution is possible using our IR room locators with our IR-enabled tags and readers.
Q: How many tags can a typical active reader read at one time?
A: Our readers can sustain a tag read rate of 140 reads per second.
Q: What is the collision ratio to number of tags?
A: Our readers can sustain a tag read of 140 reads per second. Typically, our tags are beaconing at 10 second-intervals so a single reader is handling 1400 tags easily.
Q: In an open field, what is the general range of active tags "all three frequencies?"
A: The read range of a tag from a reader is related to much more than its frequency (protocol, antenna types, tag orientation, etc.) so I can't answer for non-RF Code tags. However, RF Code tags have a typical range of 300 feet.
Q: in the estimate slide, how was the audit done? Pen & paper? Bar code scanners? (We're taking 0.5 minute/device using bar code scanners or 40 hours for 4000 devices with an efficiency rate of 75-80%.)
A: The audit was done with a bar code scanner for a large set of distributed assets (not data center assets) so the amount of time included was moving around from asset to asset, room to room, etc. The average time per asset (total inventory collection time divided by the total number of assets) was 4.8 minutes per asset.
Q: How easy is it to access the battery? Can anyone remove and thus render it non-active?
A: For tags that have replaceable batteries (which are typically the sensor tags only), the battery is fairly easy to reach. However the system will alert you when a tag no longer "beacons.” For asset tags, you typically don't want replaceable batteries for the reason you state. That’s why we don't recommend enclosures with replaceable batteries for asset tags in most situations.
Q: Numbers on cost for inventory doesn't make sense: 8 people 4 weeks twice a year is 2560 hours divided into $216,000 equals $84.37 an hour. Why?
A: The $84.37 an hour is the typical hourly burden rate of the employee. The burden rate is the total employee cost (salary, insurance, benefits, office space, etc.), not just their hourly wage. Regular IT employees were used for the audit so the burden rate about $85.00 per hour. In some IT shops the rate can be as high as $140 per hour depending upon how the organization calculates burden rate.
Q: What is the cost of readers?
A: Fixed or zonal readers have a US list price of $1249.00 and rack readers have a cost of $595.00 (USD).
Q: How does IR impact total cost of an active tag system for room level locating?
A: An IR enabled tag has a US List price (no volume) of $24.95. The IR Room locator has a US list price of $169.00.
Q: What are the prospects for lowering tag costs and size?
A: Tags costs can easily be lowered by purchasing in volume, and our sales representatives can take you through the volume discounts. Tag size is something that RF Code is constantly working on and making improvements on. However, the size and dimensions of all active tags is limited by radio frequency physics (which dictate antenna size) as well as by the required presence of a battery.
Q: How do you combat the issue of “bleed over” between fixed readers (i.e., when active tags are being read by fixed readers in multiple different locations)?
A: "Bleed over," as you call it, is natural and expected with active RFID. The RF Code software analyzes all of the tag reads gathered from all of the readers that see the tag and determines, based on user configurable rules, the zone in which the tag is located. This is mainly done via probability based rules using SSI (signal strength indicators) and user configurable timeouts. Essentially, the software handles all of this and presents a user with a single location that the tag is in.
Q: How many tags can a reader handle per second?
A: Our readers can sustain a tag read rate of 140 reads per second. Typically our tags are beaconing at 10 second intervals so a single reader is handling 1400 tags easily.
Q: What will be the best moment for tagging? Typically items will only be tagged upon commissioning. This would leave a gap for the initial receiving in the stock. Can this easily be solved?
A: RF Code recommends tagging all assets as they are unboxed and received—before commissioning. This method prevents assets from not being tagged and allows you to know the number of assets in storage waiting on commissioning.
Q: What interferences exist with the technology, i.e., RFI?
A: There is always the potential for RFI (radio frequency interference). With RF Code products that operate at 433MHz there is much less potential RFI than at the other 2 frequencies (800/900MHz and 2.4GHz). We have had no customer issues with RFI issues that could not be worked around. In one or two cases we have had a high noise level (how RFI is manifested at the product level) and it resulted in a few more readers needing to be deployed as the noise level reduced the tag read range of the readers.
Q: Are there RFID intrinsic devices available for refinery use?
A: We do have I-Safe certified tags that can be used in a refinery scenario. Our sales team will be happy to provide you more details.
Q: How is the read range of these tags affected by the surroundings?
A: typically, 2 things affect the read range for 433MHz tags: the presence of metal and high noise level in the 433MHz band. Typical office surroundings and buildings have little effect on RF Code tags. In a data center with tags placed inside metal racks with doors and sides, we can read the tags within 2000 square feet of the reader (worst case).
Q: Which is a better approach for triangulation: RSSI or TDOA?
A: Triangulation is best done by TDOA. RSSI will have issues due to multi-pathing.
Q: Can an active tag be used in aviation?
A: According to FAA rules, active tags must be turned off. RF Code provides a device to "turn off or disable" the active tag.
Q: Do you have Wi-Fi enabled readers (to avoid installing network cables)?
A: Yes, we do have Wi-Fi enabled readers and POE enabled readers.
Q: In the Government example can you provide additional details (such as how many sites were covered? Was the monitoring done at a rack level or floor level? What was the cost of the infrastructure to enable the active monitoring?
A: In the government example the site was about 3 buildings for mostly distributed (non-data center) assets. Some critical data center systems were tagged but fixed readers were used to read those tags as well.
Q: Does your application integrate with BMC REMEDY?
A: Our applications can send http post, email and SNMP trap notifications to BMC Remedy out of the box. Tighter integration is via the open API included with the RF Code products.
Q: How are tag mounted on the equipment? Can they be easily removed by thieves?
A: The tags are generally "stuck" to assets using a very strong adhesive. Once the tags have been stuck on, you typically have to almost destroy the tag to remove it. In addition, some tags have a tamper detection switch that will let you know if it is removed from the asset.
Q: What is the backend solution architecture and cost for active RFID?
A: We assume by "backend solution cost" you mean the software. The RF Code Asset Manager software has a list price of $10K and can manage up to 1000 assets out of the box. The RF Code sensor Manager has a list price of $5K and can manage 100 sensors out of the box.
Q: If I have rack mounted devices and want to have a passive tag on the device, because of the close proximity to other racks will the item be reported in the right rack? What is the proximity of the scanner, etc?
A: The question is a little confusing but we will attempt to answer it. (If we did not "get your question," please let me know and we will try again.) With rack mounted assets and the RF Code rack readers, the active RFID tags are attached to each asset in the rack. The RF Code solution has a 95% accuracy rate of identifying the correct rack that the asset it is. The 5% of the time that we are incorrect, the asset is located one rack to the left or 1 rack to the right.