Foxboro DCS Field Control Processor FCP280 LED Indicators

LED Indicators

The light-emitting diodes (LEDs) on the front of the FCP280 module provide a visual indication of the

- FCP280 operating status

- Transmit/receive communication activity on the four extended fieldbus channels

(Fieldbus A and B on each channel) LEDs on copper or fibre optic

network adapters provide visual indication of the following

- Internal and external power supply health status

- Communication activity with the control network A and B links and the FCP280

Enhanced reliability (fault tolerance)

The FCP280's unique, patented fault-tolerant operation improves 

reliability compared to traditional process controllers.

The fault-tolerant version of the FCP280 consists of two modules operating

 in parallel with two Ethernet connections to the control network.

The two FCP280 modules are combined as a fault-tolerant pair,

ensuring continuous operation of the controller in the event of any hardware failure in one of the modules.

Both modules receive and process information simultaneously and faults are detected by the modules themselves.

One important method of fault detection is to compare the communication messages of the modules' external interfaces.

A message leaves the FCP280 only if the two FCP280s agree on the message to be sent (bit for bit match).

Once a fault is detected, both modules run self-diagnostics to determine which module is affected.

The modules run self-diagnostics to determine which module is affected. 

The unaffected module then takes over control without affecting the normal operation of the system.

This fault-tolerant solution offers the following key advantages over redundant-only controllers

Redundant controllers only:

- No error messages are sent to the field or to applications using the controller data,

because unless the two modules match exactly bit-for-bit in sending a message, the

No information is allowed to flow out of the controller.

- The secondary controller is synchronised with the primary controller,

which helps to ensure that the most up-to-date data is available in the event of a primary controller failure.

- Since the secondary controller performs exactly the same operations as the primary controller,

potential defects can be detected prior to any switchover.