schneiderI/A Series® Hardware Control Processor 40

The Control Processor 40 is a high-end optionally 

fault-tolerant station in the Control Processor family 

(CP10, CP30, CP40) that has: 

• a larger memory capacity to support a greater 

number of blocks

• a faster processor for increased block processing 

With high performance, the CP40 is both economical 

and in line with today's advancing technology. Other 

members of the CP family are easily upgradable to 

CP40 capabilities.

The Control Processor 40 performs regulatory, logic, 

timing, and sequential control together with 

connected:

• Fieldbus Modules (FBMs)

• Fieldbus Cluster I/O Cards (FBCs)

• SPECTRUM Migration Integrator I/O

• SPEC 200 Migration Integrator I/O

• SPEC 200 MICRO Migration Integrator I/O

It also performs data acquisition (via the Fieldbus 

Modules), alarm detection and notification, and may 

optionally serve as an interface for one or more Panel 

Display Stations.

The non-fault-tolerant version of the Control 

Processor 40 is a single-width processor module. The 

fault-tolerant version consists of two single-width 

processor modules.

Enhanced Reliability

The Control Processor 40 offers optional faulttolerance for enhanced reliability. The fault-tolerant 

control processor configuration consists of two 

parallel-operating modules with two separate 

connections to the Nodebus and to the Fieldbus.

The two control processor modules, married together 

as a fault-tolerant pair, are designed to provide 

continued operation of the unit 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. 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.

To further ensure reliable communications, the faulttolerant control processor performs error detection 

and address verification tests in its Nodebus and 

Fieldbus interfaces. 

For enhanced reliability during maintenance 

operations, the Control Processor 40 is equipped with 

a recessed reset button, located at the front of the 

module. This feature provides for manually forcing a 

module power off and on (reboot) without removing 

the module from the enclosure.

Diagnostics

The Control Processor 40 uses three types of 

diagnostic tests to detect and/or isolate faults:

• Power-up self-checks

• Run-time and watchdog timer checks

• Off-line diagnostics

Power-up self-checks are self-initiated when power is 

applied to the control processor. These checks 

perform sequential tests on the various control 

processor functional elements. Red and green 

indicators at the front of the control processor module 

reflect the successful (or non-successful) completion 

of the various phases of the control processor startup 

sequence. 

The run-time and watchdog timer checks provide 

continuous monitoring of control processor functions 

during normal system operations. The operator is 

informed of a malfunction by means of printed or 

displayed system messages.

Off-line diagnostics are temporarily loaded into the 

system for the purpose of performing comprehensive 

tests and checks on various system stations and 

devices. Using the off-line diagnostics, a suspected 

fault in the control processor can be isolated and/or 

confirmed.

Fieldbus Modules 

Fieldbus Modules provide connection of digital I/O, 

analog I/O, and Intelligent Transmitters to control 

processors. There are two types of Fieldbus Modules: 

Main and Expansion. Some main modules can be 

expanded using an expansion module.

A wide range of Fieldbus Modules is available to 

perform the signal conversion necessary to interface 

the control processor with field sensors and 

actuators. For further information on the Fieldbus 

Modules, refer to the Fieldbus Modules Product 

Specification Sheet (PSS 21H-3B1 B3).

Fieldbus Flexibility

The Control Processor 40 is used in three different 

Fieldbus configurations, which provide broad flexibility 

in Fieldbus implementation:

• Local Fieldbus (Figure 1) - Used only within the 

enclosure, the local bus can extend up to 10 m 

(30 ft). Up to 24 Fieldbus Modules (excluding 

expansion modules) attach directly to the local 

bus, which is redundant

• Twinaxial (Dual-Conductor Coaxial) Fieldbus 

Extension (Figure 2) - Using twinaxial cable, the 

Fieldbus can optionally extend outside of the 

enclosure and can be up to 1800 m (6000 ft) in 

length. Up to 64 Fieldbus Modules (excluding 

expansion modules) attach to the extended bus 

through Fieldbus isolators. (Up to 24 Fieldbus 

Modules, excluding expansion modules, can