With only 3 wires, an LED, and an antenna coil, the xEM Access Controller is a simple, easy to use stand-alone RFID access controller. It has a built-in RFID reader, microprocessor, and memory system that allows you to easily store a list of up to 20 tag IDs in an “authorized list” within the access controller’s internal memory. You don’t need an external computer or microcontroller, this is a complete stand-alone system. When an authorized ID is read from a chip, the OUT line puts out +12v for as long as the authorized device is held over the antenna.
xEM Access Controller Details
- Operates on +12v DC power
- Reads EM4200 (EM4102 compatible) 125kHz 64bit tags
- Store up to 20 RFID tags in the authorized tag list
- Two keyfobs and a master programmer tag included
- 2.1″ x 1.3″ cylindrical antenna (works great with x-series chips like the xEM)
- Antenna connected to controller by 20″ coax cable for easy installation
- Controller encased in automotive grade 4 1/8″ x 2 1/8″ plastic box
- Red “authorized tag” indicator LED connected by 40″ wire
- Black plastic panel mount/holder for LED included
- Draws 11mA idle, 48mA reading authorized tags (no load on OUT line)
Wiring & Operation
To get started, connect the red wire (some units have a yellow wire instead of red) to +12v DC power. Connect the black wire to ground. The white wire is grounded until an authorized tag is presented to the reader antenna, at which point it outputs +12v
WARNING Do not apply +12v to the white output wire. This will immediately damage the access controller and render it useless.
When an authorized tag is presented to the reader antenna, while the tag is in range of the antenna, the red LED indicator will light up and the white signal wire outputs +12v to be used by an external device like a very small motor, relay coil, solenoid, or trigger an external digital system (with proper voltage regulation). Once the tag is removed, the LED goes dark and the white signal wire goes low (0v). If an unregistered tag is presented, it is considered unauthorized and the LED will not light, and the white signal wire remains low (grounded).
Programming the xEM Access Controller
The xEM Access Controller can store up to 20 tag IDs in non-volatile memory. Each reader comes with a “master tag” which is shipped in a metal tin, and is used to add new IDs into memory.
- To program a new tag ID into the controller’s non-volatile memory, swipe the master tag across the reader antenna, then immediately swipe the tag you wish to add across the reader antenna (within 3 seconds).
- To erase tags from the controller’s memory, hold the master tag to the reader antenna for 10 seconds.