UCOS Field Control Unit (FCU)

The UCOS Field Control Unit directly scans and controls multiple brands of I/O modules and executes event-driven logic.

The UCOS Field Control Unit (FCU) runs the sequential and regulatory control schemes downloaded to it from the UCOS Engineering Workstation (EWS).

It performs logic processing according to those schemes and in response to operator commands.

The FCU optimizes network efficiency by relying on exception-based data reporting strategies in communicating with the UCOS Operator Workstation (OWS) and other FCUs. Real-time information is stored in memory for global use throughout the UCOS control system.

The unique flexibility of this technology allows the UCOS FCU to directly connect to standard, off-the-shelf I/O subsystems.

The FCU runs on processors available from a variety of manufacturers in a variety of form factors, including PLCs for ultra-reliable performance and ruggedized industrial controllers for cost-efficient architectures. The illustrations shown here are just examples.

Details

The FCU supports all the real-time functionality requirements of an industrial controller, including:

• Control scheme execution
• Data acquisition and calculation
• Regulatory and sequential control
• Interlocking
• Event-initiated processing
• I/O scanning
• Industry-standard, POSIX-compliant operating system
• System communication via single or dual wireless TCP/IP Ethernet connection
• Direct scanning of I/O

Real-Time, Multi-Tasking Operating System

Each FCU is directly connected to the same network as the Engineering and Operator Workstations. The FCU operates under just about any POSIX-compliant operating system, such as Linux, QNX, UNIX, Windows, etc. UCOS lets you choose the operating system that meets your needs:

• Ultra-reliable, real-time, multi-tasking operating systems or ...
• Cost-efficient industry standard operating systems with broad connectivity support

Depending on the form factor, the FCU can be equipped with flash disks, non-volatile memory, and an optional internal backup power supply to help ensure continuous processing in the harshest of environments.

In addition, UCOS supports selective redundancy at all levels, including redundant FCUs and redundant I/O points.

At run-time, the FCU software:

• Receives commands and data from one or more operator workstations and/or one or more input/output interfaces that communicate with field devices (e.g. pumps, valves, etc.)
• Processes and solves in real-time all logic generated during the project development phase
• Communicates the results to the Operator Workstation and/or input/output interfaces

Event-Driven Logic Processing

Logic processing is performed by the FCU according to the schemes developed during project configuration on the Engineering Workstation. The processing is completely event-based. Every device configured in a device diagram is represented in a device table residing on the appropriate FCU. All the logical relationships are represented in a device-specific event list that logically relates source (occurrence) and destination (triggered response) events.

When an event occurs at run-time, the logic processing engine uses the appropriate event list to determine what action (if any) to execute. That action may, in turn, trigger other events and actions. The real-time executive ensures that critical control functions take precedence over other operations and that logic is executed in the correct sequence.

Real-time information and device control status are stored in the FCU's logic solver. Data updates are reported by exception. This frees the system from the scan rate limitations that can affect real-time processing and reporting of data at the Operator Workstation. It also minimizes network traffic allowing FCUs to be located remotely.

Supports Multiple Brands of I/O in Each Unit

Standard vendor-manufactured I/O scanner cards are plugged directly into the FCUs that are based on industrial controllers. These cards provide access to I/O networks, which are scanned directly by the FCU. FCUs based on PLCs can directly scan just about any I/O supported by the PLC.

UCOS supports multiple vendor I/O subsystems at all levels. A variety of distributed I/O networks can be accommodated in the same or different FCUs.