GE Fanuc’s CMX shares control data up to 200 times faster than Ethernet

Charlottesville, VA—GE Fanuc Automation Americas Inc. has introduced its new PACSystems Control Memory Xchange (CMX) that increases data acquisition capacity and reliability, even in the harshest electrical noise environments.

By Control Engineering Staff May 28, 2004

Charlottesville, VA— GE Fanuc Automation Americas Inc. has introduced its new PACSystems Control Memory Xchange (CMX) to increase users’ product quality and boost uptime by increasing data acquisition capacity and reliability, even in the harshest electrical noise environments. CMX will be available for the PACSystems RX7i platform in July 2004, and additional platforms will follow later.

Developed with GE Fanuc’s patented technology, which already has been proven in many industries and applications worldwide, CMX allows multiple devices to share large amounts of control data over a fiber-optic deterministic network at speeds reportedly up to 200 times faster than Ethernet. To increase automation performance and reliability, this high-speed memory-sharing application operates in parallel to the main logic CPU with virtually no effect on the scan time of the control processor. CMX also offers improved security over Ethernet, which operates on an open protocol, and supports the distance requirements to physically separate redundant processors into different cabinets or buildings in critical applications with potential homeland threats.

High-speed memory sharing By acquiring large amounts of data at very high speed via CMX, users can quickly adjust process parameters and achieve tighter synchronization between control systems, which can increase product quality and reduce material scrap. Applications that can benefit from CMX include paper production; metals forming, finishing and extracting; cement crushing and conveying; oil and gas processing and distribution; wind tunnel testing; chemical dispensing; painting; batch processing; and any other process requiring high-speed, high-volume data acquisition for high-resolution measurement and fast response.

Also, CMX allows users to capture process and regulatory compliance data at tighter frequencies, which can help companies more precisely measure process performance. With greater bandwidth and capacity, users can also acquire more parameters for future process analysis. Manufacturers can augment data management systems, such as GE Fanuc’s iHistorian software, with CMX to combine high-speed communication and processing with powerful archiving capabilities.

CMX technology The CMX controller writes data to shared memory, and this technology immediately and automatically broadcasts the data to all other nodes on the network. GE Fanuc reports that this automatic data transfer requires no software overhead or host processor intervention, enabling the PACSystems CPU to devote its processing resources to the control application and reducing the cost and time typically associated with software development.

Available in multiple control form factors for controllers and PCs—such as VME, PCI and PMC—CMX allows users to easily share data in real time at rates up to 174 Mbps with node-to-node latency as low as 450 nanoseconds. Users can realize updates on 10,000 data tags from input controller to second controller or screen display in as little as 1 millisecond. This simple, powerful “shared memory” architecture provides real-time speed and deterministic performance without the data collisions and latencies that can plague other network technologies.

In addition, CMX permits data sharing between up to 256 independent systems or nodes, allowing plant-wide data transfers. Each controller or computer keeps a local copy of shared data for fast real-time use. Noise immunity in the fiber-optic system increases reliability and eases installation. Furthermore, the system features an OPC server to connect with GE Fanuc’s Human Machine Interface (HMI) software and other software. The technology also is operating system independent, making it easy to implement in a variety of applications.

Control Engineering Daily News DeskJim Montague, news editorjmontague@reedbusiness.com