EM4100 Reader pinouts
Reader Pinouts and specs
Most of the Wiegand protocol readers available use similar wiring and pinouts. Here are some general and specific guidelines.
EM4100 Readers
The EM4100 readers we sell have this pinout:
- Red = +12V Power (25-100ma)
- Black = Ground/negative power terminal
- Green = Data 0
- White = Data 1
Optional:
- Blue = LED (ground this wire to change LED state)
- Yellow = Beeper (ground to to turn on)
The Open Access Mega board has all of these labelled on the header. There are (3) outputs for red led, green led and buzzer lines, which can all be addressed via the software. The last pin is can be attached to the cable shield if shielded wire is used.
Card Format
The ACCX-supplied readers and cards use a Wiegand-26 format.
Card format: 26-bit (8-bit facility code, 16-bit user ID, two parity bits)
P DDDDDDDD DDDDDDDDDDDDDDDD P
Electrical signalling:
A ‘0’ and a ‘1’ line are held at +5V relative to ground. When data is transmitted, the lines are sent low for a period of between 35-500uS (measured) with a pause between bits of approximately 10X the pulse width. Reader lines can be up to 500’ from the panel.
Initial Testing
For tips on initial testing, see the testing page: