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Bus Interface Unit (BIU)

 

 Bus Interface Unit
The Bus Interface Unit (BIU) functions as the link between the host vehicle and the Passenger Counting computer. 

BIU Features

     
  • EMI & transient protection for all inputs 
  • Circuit breaker for short-circuit protection 
  • 12 Vdc & 24 Vdc versions available 
  • High efficiency voltage regulation 
  • Level-sensitive Door Switch & Engine Status interfaces 
  • Odometer interface for analog or digital signals 
  • Auto power-up based on Engine Status 
  • Power-down under PCU control 
  • LED Indicators for power & signal status 

Detailed Description

The Bus Interface Unit contains all the interface circuitry for the System Power, Engine Status, Door Switches, and Odometer Signal. All inputs are protected with EMI filtering and transient protection. System Power circuit breaker also functions as an ON/OFF switch for system maintenance. Status indicator LEDs on the front allow for monitoring of these system inputs. Door Switch and Engine Status inputs are level-sensitive, based on a percentage of the system voltage, preventing false indications during fluctuations in vehicle power. Both 12 Vdc & 24 Vdc versions have high efficiency switching regulators. 

Updated 08 Feb 2002
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