The unique and patented fault-tolerant operation of the FCP270 greatly improves reliability relative to other process controllers. The fault-tolerant version of the FCP270 consists of two modules operating in parallel, with two Ethernet connections to The MESH control network. The two FCP270 modules, married as a fault-tolerant pair, provide continuous operation of the controller in the event of virtually any hardware failure occurring within one module of the pair. Both modules receive and process information simultaneously, and faults are detected by the modules themselves. One of the significant methods of fault detection is comparison of communication messages at the module external interfaces. Messages only leave the controller when both controllers agree on the message being sent (bit for bit match). Upon detection of a fault, self-diagnostics are run by both modules to determine which module is defective. The non-defective module then assumes control without affecting normal system operations.

This fault-tolerant solution has the following major advantages over controllers that are merely redundant:

No bad messages are sent to the field or to applications using controller data because no message is allowed out of the controller unless both modules match bit for bit on the message being sent.

The secondary controller is synchronized with the primary one, which ensures up to the moment data in the event of a primary controller failure.

The secondary controller will have latent flaws detected prior to any switchover because it is performing exactly the same operations as the primary controller.

SPLITTER/COMBINER

Fault-tolerant FCP270 modules connect to a pair of fiber optic splitter/combiners (see Figure 1) that connect to Ethernet switches in The MESH. For each module, the splitter/combiner pair provides separate transmit/receive fiber connections for Ethernet switch 1 and 2. Fiber cables are connected so that the splitter/combiners pass inbound traffic from either switch to both modules, and pass outbound traffic from the primary module to either switch.

The splitter/combiner pair mounts in an assembly that fastens to the FCP270 baseplates. The splitter/combiner is a passive device that uses no electrical power.

ENHANCED COMMUNICATIONS

The Foxboro Evo architecture uses The Mesh control network with 100 Mbps data communications between the FCP270s and the Ethernet switches (see Figure 2)

When used with the FBI200 or FBI100, the FCP270 can communicate with both the 100 Series and 200 Series FBMs (dual baud functionality, which requires I/A Series software level v8.4.1-v8.8 or Control Core Services v9.0 or later). It connects to the 2 Mbps HDLC fieldbus for communications to all 200 Series I/O FBMs and the Siemens APACS+™ and Westinghouse® competitive migration modules. When used the 100 Series FBMs and 100 Series competitive migration modules, the FCP270 connects to the 268 Kbps HDLC fieldbus, via the fieldbus splitter/terminator. (See “DEVICES SUPPORTED” on page 8.) The optional FBI200 or FBI100 filters the 2 Mbps messages from the 2 Mbps/268 Kbps mixed HDLC fieldbus and only passes on the 268 Kbps messages for the 100 Series FBMs. The FCP270 can also communicate with serial and Ethernet devices, such as PLCs, via Field Device System Integrators. This allows you to connect to new device interfaces without any changes to the controller software.

UPGRADE OPTIONS

Multiple options are available for replacing control processors controlling 100 Series FBMs with the FCP270 in a Foxboro Evo network.

Cabling the 100 Series FBMs or Migration products to an FCP270 baseplate consists of extending the remote 268 Kbps fieldbus between enclosures. This is accomplished using termination cable assemblies (TCAs) and Fieldbus Isolators (FBIs) to provide connections between primary and extended fieldbus segments. For direct connections from the FCP270 to the 100 Series FBMs, the maximum fieldbus length is 1 km (3200 ft). An FBI100 can be used to extend the fieldbus to 1.83 km (6000 ft).

As with earlier generations of control processors, up to 64 Fieldbus Modules (including 100 Series FBM Expander Modules) attach to the extended bus through Fieldbus Isolators. (Up to 24 Fieldbus Modules, excluding expansion modules, can connect to each isolator.)

　　Model recommendation:
FBM207C RH917GY FOXBORO
FBM219 RH916RH FOXBORO
FBM237 RH914XS FOXBORO
FBM242 RH916TA FOXBORO
FCP280 RH924YA FOXBORO
H92 I/A SERIES FOXBORO
H92 FOXBORO
RH916DD FOXBORO
RH916ND FOXBORO
RH916TA FBM242 FOXBORO
More……