TINI Access Control System


Table of Contents

  1. Overview
  2. Downloads
  3. Installation
  4. Operation
  5. Sample Network Commands
  6. Performance

Overview

Controlling access to secured areas has long been a challenge. The solution requires balancing many sometimes-conflicting factors.

This uniquely net-centric solution (reference design) is built around the powerful TINI platform and iButtons® (keys) from Dallas Semiconductor. iButtons provide the user the convenience of a "Touch and Go" entry, while TINI® provides Internet connectivity for administration and key management.

How do you use it? Simply press the reader (called a Blue Dot Receptor) with your iButton and you’re in. This simple procedure is fast, reliable and secure. The willful act of touching prevents eavesdropping or accidental activation.

The iButton is a sophisticated microchip with a unique identity, which is surrounded by a stainless steel shell. Its round shape integrates easily into a credential that fits the user’s lifestyle.

SYSTEM OVERVIEW

By leveraging the 10-Base-T network, each TINI can manage up to four access points and bringing them under centralized administration. The system can be expanded with additional TINI’s in effective cost increments. Additionally, each TINI keeps the access list locally for fast user response and can therefore operate even if the 10-Base-T network is down.

THEORY OF OPERATION

At each access point is a low cost 1-Wire door controller, which consists of a DS2409 (high side switch), DS2406 (addressable switch), LM555 (adjustable oscillator) and the BlueDot receptor (with LED) (DS9092L).

When an iButton is pressed to the Blue Dot Receptor at the door entrance, TINI reads its 64-bit 1-Wire address and compares to a local list of valid buttons. If there is a match, TINI activates the electronic door strike over the 1-Wire net.

A good choice for the electronic door strikes is Securitorn’s UnLatch®. It is motorized, sized to a commercial door strike plate and easily installs into the door jam. TINI activates this strike with a short pulse on the UnLatch’s "Trigger" input. This smart strike then does the rest. (Note this strike will only work with cylindrical door lock sets.)

THE POWERFUL 1-Wire NET

Using the DS2409 as a node ID on a 1-Wire net, the TINI can address different modules or doors. When addressed, the DS2409 opens either Channel A or Channel B allowing the TINI to see other devices connected to that channel. Internal registers in the DS2409 provide pseudo interrupt capability so that TINI can detect activity on the DS2409's sub-net without being connected to it. When an iButton is presented to the Blue Dot, it generates a presence pulse. This pulse triggers the interrupt register in the DS2409 to respond to the interrupt search from the TINI. An alternate method is standard polling of each door Blue Dot Receptor. This reference design utilizes the later method.

The DS2406 has two channels. Channel A is setup as an output to drive the relay. (A relay is suggested to provide isolation and support higher currents.) Channel B is setup as an input to read a switch (magnetic reed switches are commonly used for door status).

The LM555 (or any generic brand of 555 oscillator) is added to lessen the communication over the 1-Wire net. The LM555 will create pulses to drive the LED in accordance to the Blue Dot specification. Using the relay output of the DS2406 to pull down the Reset of the 555, the LED will be turned on as long as the relay is energized. The CTL output of the DS2409, when pulled low, will cause the 555 to hold the LED dark as long as it pulled low.

The Securitron UnLatch was chosen because of its compact design, ease of installation and built-in door status switch. For additional information, contact Mark Henderson at Securitron Magnalock Corp. Phone: 702-355-5625. To be compatible with the TINI unregulated power supply, request the +12V model.

The schematic and layout of a PCB that fits into a standard NEMA single gang box is provided.

Downloads

Installation

The following information assumes that the reader is familiar with building and running applications on the TINI platform. For detailed information on TINI, please see http://www.ibutton.com/TINI/index.html.

The NetworkLockServlet has been tested with TINI 1.02 and TiniHttpServer0.14.

  1. Download TINI 1.02 from ftp://ftp.dalsemi.com/pub/tini/tini1_02.tgz.
  2. In order to run the NetworkLockServlet, TiniHttpServer needs to be installed as well. TiniHttpServer can be downloaded from http://www.smartsc.com/tini/TiniHttpServer/docs/index.html. Follow the instructions given there.
  3. For information on using NetworkLockServlet with TiniHttpServer0.12, please see THS0.12setup.html. For TiniHttpServer0.14, please see THS0.14setup.html.
  4. Make sure that the door lock circuit is connected to TINI. The LED should start flashing. Open a telnet session and run TiniHttpServer.tini by typing at the TINI prompt:
    source /bin/TiniHttpServer
  5. You should see the following message:
    NetworkLockServlet: init
    which indicates that the NetworkLockServlet is up and running.
  6. Open your favorite browser and type in a URL similar to the following:
    http://www.your_tini_url/NetworkLock.html
    The log in page now appears.
  7. Log in with:
    Username = admin
    
    Password = tini
    
    
    Note that both the username and password are case sensitive.
  8. Click on the "Start Circuit" link to activate the lock. Status in the initialization process will appear in the right frame. Once initialization has completed, place a valid iButton on the Blue Dot receptor, the door LED will light up indicating that access has been granted. If you touch an invalid iButton on the receptor, the LED should stop flashing. It will remain off for a couple of seconds, indicating access is denied.

Operation

Door LED blinking Door lock is operational and is waiting for valid iButton.
Door LED ON If a valid iButton is detected, access is granted and the door LED will stay ON for DOOR_OPEN_MILLIS millisecond.
Door LED OFF Either the lock is disabled or invalid iButton is detected. In the case where an invalid iButton is detected, access is denied and the LED will stay OFF. The door will resume operation after DOOR_DISABLE_MILLIS millisecond. 

Sample Network Commands

Log In Administrator log in page. ALL administrative functions require log in to verify authorized access.
Log Out Log out page. Terminate administrative rights for this log in session.
Start Circuit Start lock circuits. Log in required.
Stop Circuit Stop all active lock circuits. Log in required.
Open Door Open door from a remote host. A list of available door circuits are displayed and the user can select from the list. Log in required.
Add User Add in authorized user. Administrator needs to supply user name and a valid iButton serial number. Log in required.
Remove User Remove user access. Administrator needs to supply a valid iButton serial number. Log in required.
Display All Users Display all authorized users. Log in required.
Change Password Change administrator password. Administrator needs to supply "User Name", "Old Password", "New Password" and "Confirm New Password". Log in required.
Commit Changes Commit changes to memory. Any changes not committed will be lost on next TiniHttpServer launches. Log in required.

Performance

Empirical results indicate that less than 100 mS are required to detect the iButton and open the lock. Response time is directly proportional to the number of locks monitored by the TINI module and the number of processes active.