2-4  Theory of Operation 
 
Name Function 
Magnetic Stripe 
Registration 
This is a reflective sensor that locates the leading edge of the card for 
magnetic stripe encoding. When no card is present, the sensor beam 
reflects off a plate on the magnetic stripe rocker. When a card passes 
between the sensor and the reflector, the beam is broken (not reflected). 
The sensor itself is active when no card is present, but the signal is inverted 
elsewhere in the system. 
For the clear card option, this sensor is replaced with another reflective 
sensor. 
Magnetic Stripe 
Optical Encoder 
This encoder monitors the rotation of the idler roller in the magnetic stripe 
module. It provides positional feedback to the module to ensure proper 
magnetic encoding. 
Duplex Entry 
The duplex entry sensor is an optical interruption sensor that detects the 
presence of a card as it enters and leaves the duplex module. 
For the clear card option, this sensor is replaced with a reflective sensor. 
Duplex Home 
The duplex home sensor determines the rotational position of the duplex 
flipper. The flipper has three flags that pass through the sensor. 
Input Hopper 
Empty (Optional) 
This reflective sensor detects when the card hopper has no cards left. It 
functions only when special software is created to use it.