Subscriber Discussion

Passive Personal Tracking With Long Range Readers?

Hey all. I have a customer that has HID prox corp 1000 cards. They want to know when people are leaving. They know after I explained to them that someone having a conversation near any solution wouldn't be any functionally different than someone passing through the door, so they're aware of that.

Basically, they want to know when people are leaving. They have to read in to get in, so they will know when people come in (minus potential piggybacking), but they want something on the egress side that will tell the system when people are leaving.

We have discussed read-out with anti-passback, read-out with delayed egress, but they have decided that they want a passive solution that works if the card is in someone's pocket. I will do an interface with the access control and video so that the card number gets timestamped on the video every time someone passes the reader. That way, if they're trying to figure out someone's movements, they can just do a search in the video system and see if they actually went out the exit or just passed by it.

I spoke with HID, and they will not guarantee that their long range readers will work in this fashion. Anyone have any other ideas?

Thanks a ton.

I tested this with their long range readers and they do not work. I even set up a mock doorway with a long range reader on each side and there was no guarantee for it to work. Maybe you can do it with an active tag but that would require an investment in new cards plus I still do not think there would be a guarantee it would work 100% of the time. I ran into this all the time when I worked for an Integrator, they wanted to the benefits of read in/out and anti passback but did not want to have people read out. We just tried to explain it's a change in procedure and culture. You either do it right or do not do it all.

Nedap AVI has a really long range card reader that goes up to 4m/~12', but I have no idea if it could read a card in a pants pocket or purse. It would be interesting to test through.

We used Nedap with great success but never indoors, it would be worth a call to their Engineering to talk though.

This is tough. Would turnstiles be an option? Ensuring that people exiting are within proximity range and at a semi-standard velocity would only help a long-range reading solution.

Crashing two or three people near abreast through an exit would be tough for a long range reader to scan. You'd almost need to ensure one-at-a-time.

If they'd be willing to work outside the existing reader cards, they could go with an independent situational awareness system like AeroScout or equivalent. This would give them the added benefit of situational awareness at all times within the facility (works in conjunction with existing Wi-Fi). Using a choke point monitor(s); the "conversation near any solution" would be eliminated as this system will only register if the tag actually passed through the point.

Recording and archiving may have to take place outside the current access control system unless an interface exists (or can be created) that would feed this data to the existing access control software. The additional investment is dependent on how important it is they know this information, just how accurate it has to be, and would they see added value in other benefits for such things as emergency (panic button), disaster recovery, fire evacuation confirmation, even asset tracking could be another factor in justifying the investment. I hope that adds to the thought process and good luck with your solution.

I don't know of any reliable hands-free reading solution that will work with passive credentials.

As soon as the card is in your pocket or in a purse (metal interferes with RF), read accuracy diminshes so much that you cannot be guaranteed to get a read. The only thing that will ensure a read would be an active tag (so that would require changing out their credentials).

You need to force the card users through an entry and an exit choke point (physical turnstile, optical turnstile, etc...) and have them present their cards to a reader. Error-free (i.e: no false reads or accidental reads) hands-free doesn't work with passive 125 KHz credentials.

Hello Nick and others,

I work for Nedap (Nedap AVI) and may be able to shed some light on this matter.

We do offer a small UHF reader that fits on a doorpost and is still able to support a read range of approximately 2 meters (6 feet) when using passive UHF cards. We also offer combi cards that combine UHF with HID prox (uPass Access).

The tricky part of your question is that you want the cards to be read even when they are inside the pocket. That is difficult. UHF cards that are in contact with the body will offer a very small read range because of bodily fluids that absorb the signal. If the card is away from the body a little (like when it is on a lanyard), it will work much better.

An alternative would be to consider (semi)active systems, like our microwave based system: Systems like these use proprietary tags that contain a PCB and battery and are able to support a read range of multiple meters. The compact tags that are used with this reader will last for approximately seven years. But it seems your customer is insisting on a passive solutions.

Nedap also has inductive passive card technology available that approximately operates at the frequency of HID prox cards (120 kHz). We have readers with enlarged antennas that would potentially offer a read range of approximately one meter. Solutions like you're describing have been built based on this technology. This card technology is however not well suited for multi tagging applications.

I do agree with the people contributing to this discussion that it is important that the end user's expectations are managed well and that he/she is aware of the pros and cons of the available technical options. When in doubt I would always advise to test a proof of concept.

I do hope this helps. Please let me know when I can be of further assistance.

Hello Maarten:

Thanks for that feedback. Members, we previously profiled the NEDAP UPass after ASIS last year.