CP60 and CP60 Plus Service Manual  2-3 
 
Sensors 
All of the optical sensors in the CP60 and CP60 Plus printers are of the open 
collector type, and are configured to be active-low with a pull-up resistor on the 
output. When the sensor is not active (or not connected at all) the control board 
sees a high voltage (5V) at the Signal input. When the sensor is active, it shorts 
Signal to Ground. The diagram below is a simplified representation of an 
interruption sensor. 
 
Name Function 
Card Input 
The card input sensor is an interruption sensor that detects the presence 
of a card at the entry of the printer and registers the trailing edge of the 
card for printing.  
For the clear card option, this sensor is replaced with a reflective sensor. 
Printhead Cam 
As the printhead cam rotates, a flag on the cam interrupts the beam of 
the cam sensor. This allows the printer to know the position of the 
printhead lifters. The printhead lifters lift the printhead away from the 
platen roller when not printing. 
Swingarm Open 
(Cover arm) 
The swingarm open sensor detects when the swingarm is open. The sensor 
itself  detects when the swingarm is closed, but the signal is inverted 
elsewhere in the system. 
Note: The user information and Diagnostics refer to this as a cover arm 
sensor.  
Ribbon Index 
The ribbon index sensor is used to determine the position of the print 
ribbon panels. The sensor bounces a beam off the reflective sticker on the 
printhead. When the index mark or K-panel on the ribbon passes between 
the sensor and the reflector, the beam is broken (not reflected). The Y, M, 
C, & T panels do not interrupt the beam. 
Ribbon Motion 
The ribbon motion sensor is a two-channel optical interruption sensor that 
detects slots on the ribbon encoder wheel. The encoder wheel is located 
on the ribbon cartridge.  Internally the sensor body contains a pair of 
standard interruption sensors.