MiamiRob 0 Posted April 1, 2010 How does an access control system open a door? If someone could explain that to me, I would appreciate it. When someone scans a card or key fob on a door reader does a signal run on one wire to the server or other master device to determine if the card or fob is valid and then send a signal back on another wire to the door strike release allowing the door to open? As I correct in thinking that the door needs a card reader, some piece of hardware that replaces the strike plate and a power supply to make the strike plate mechanism releases the door when a valid card or key fob is scanned? Or are there additional pieces of hardware that are required? If a door has an electric opener, does the "open" signal both release the strike or mag lock and also activate the motor that opens the door? If a security guard would like to use access control software to remotely open a door is any additional hardware required for that door? For example, if a guard located on one floor would like to release a door to a conference room on the floor above, can he or she just click some button on the access control software console and open the door? Does a door have to have some special additional hardware to allow the door lock to released remotely using the access control software or can any door that opens with a card or fob be remotely released by a guard using software? A final question... Why are mag locks used? Are they used because they cannot be picked\because they are so hard to open? Or are they used for double doors, etc? Thank you very much. Robert Share this post Link to post Share on other sites
Soundy 1 Posted April 1, 2010 How does an access control system open a door? If someone could explain that to me, I would appreciate it. Well, that is an EXTREMELY broad question - there are SO many different ways to accomplish it! You might as well ask, how does a carpenter drive a nail? When someone scans a card or key fob on a door reader does a signal run on one wire to the server or other master device to determine if the card or fob is valid and then send a signal back on another wire to the door strike release allowing the door to open? That's pretty much it, if you're talking about a centrally-manged, card- or fob-based system. I've not seen such a thing, but I would imagine it's also possible to have the "validation" processing done entirely IN the reader unit, and simply have that managed from a central server... or to have multiple units communicate with each other and do without the server altogether. Simpler systems would have the validation done within the reader, but without multiple readers communicating with each other. Think of a home door lock with a thumbprint reader, or even with a numeric keypad: it's just a standalone device with reader and strike all integrated. As I correct in thinking that the door needs a card reader, some piece of hardware that replaces the strike plate and a power supply to make the strike plate mechanism releases the door when a valid card or key fob is scanned? Or are there additional pieces of hardware that are required? Yes. Typically the strike plate in the door jamb would be replaced with an electric strike built around a solenoid. In a 'fail-safe' configuration the strike is normally in a 'released' state to the door can be opened readily; energizing the solenoid then locks the door. In a 'fail-secure' setup, the strike is normally locked, and energizing it releases the lock. Some strikes have the option to select which method you want to use; others, you have to buy the appropriate version. If a door has an electric opener, does the "open" signal both release the strike or mag lock and also activate the motor that opens the door? It COULD. It would depend on how the installer sets it up. Typically, you'd want it to release the lock, then initiate the opener after a brief (<1s) delay, then re-lock the strike after another brief delay. But the sequence and timing could vary depending on the specific needs of that installation. If a security guard would like to use access control software to remotely open a door is any additional hardware required for that door? For example, if a guard located on one floor would like to release a door to a conference room on the floor above, can he or she just click some button on the access control software console and open the door? Yup. Does a door have to have some special additional hardware to allow the door lock to released remotely using the access control software or can any door that opens with a card or fob be remotely released by a guard using software? All it would require is something to energize the strike to cause it to release. The access control interface would more than likely be on the same server that provides the fob validation, but it wouldn't have to be. You could also have an "emergency exit" button, crash bar, or other such device paralleled with the controller, or tie it into a fire alarm system. In a lot of cases like this, you might actually use a fail-safe strike, where the system keeps it energized until you need it to unlock. That way, if you had a power outage, people wouldn't be trapped by a locked door. (Of course, you can also have other sorts of mechanical releases on the doors themselves, in conjunction with a fail-secure strike... again, the are so many different ways to do it, some of which may be dictated by local building, electrical, and/or fire codes). A final question... Why are mag locks used? Are they used because they cannot be picked\because they are so hard to open? Or are they used for double doors, etc? Plenty of reasons to opt for a maglock over an electric strike. They can have substantially more holding power. They can be used in instances where a standard strike isn't practical (all-gladd doors, for example). They tend to be a lot easier to retro-fit in many installations, because you don't need to be cutting out door jambs and fishing wire into them. I've done strike installs into steel door frames that were filled with concrete, and had to spend hours with a small air chisel and hammer drill hollowing out enough space for the strike to fit. In either case though, the idea is the same: something else - a computer, a controller, or just a simple switch, controls the electricity to the lock in order to control access. Share this post Link to post Share on other sites
MiamiRob 0 Posted April 3, 2010 Matt, Thank you for the detailed answers. They were very helpful. In our condo we are getting close to the point where we will have to make decision about signing a contract withh the security vendor. At this point, I feel that we may get a better product by hiring sub-contractors ourselves. In that I am very knowledgeable about computer networks, for the camera systems, I don't need the security company to do anything other than connect the cameras to the network switches and power supply, mount and position the cameras correctly and configured the client software on the guard workstations in the lobby. I don't reall understand all the pieces of the access control system so we would definitely need to re-bid out that portion of work. We have all the plans though so getting bids should be pretty easy. I think. I looked at your website and say the http://www.3xlogic.com/xview info. Do the large panaramic images move in real time just like regular video? How much would the hardware and software cost that would be needed to support a space like the supermarket they show in the exanple? I would like put this product in the driveway of our condo. I am going to read the info in much greater detail tomorrow. Rob Share this post Link to post Share on other sites
