The FEP performs the following tasks :

• The main task of the FEP is to gather data from distributed local systems in sub stations through the multiplex communication BUS (can be radio link, fiber optic or long distance MODEM link)

• Carry out efficient handling method of switching over hot backup redundant RTUs and redundant communication BUS

• Transfer/Convert condense control/ monitoring data from local systems to HMI which is important for short responds time

• The data from local system is buffered data into its memory so that the HMI can obtain these data with a higher speed

•  Other features of a FEP can be as a protocol converter to integrate with other systems (fire / building services, etc.)

• Provide closed loop control system (e.g. alarm annunciation, timer control operations) and other intelligent processing/ routing required in CAT II airport.

In AGLCS which require its equipment to operate with high availability, the FEP is normally equipped with another standby FEP for hot backup redundancy. A FEP in such a system requires a minimum of 3 communication links ; one for communication with the HMI computer, one with its partner (standby/main FEP) and one link connects to main BUS/standby BUS for communication with its distributed local systems (PLCs/RTUs). In a small system, the FEP is not required, the HMI computer can directly interface to a PLC/RTU which control/monitor its local Input/Output (I/O) points.
 

SCADATRON AGL Control System Front End Processor (FEP) And Control Console In Monitoring Station	Closer View  At The SCADATRON Front End Processor (FEP)