Mr. Reed Ashmore

Reed Ashmore, I/O product manager at GE Fanuc Automation (Charlottesville, Va.), points out that customers no longer limit themselves to a single vendor for the various components of a control system.Customers like the modularity available now so that they are not limited by the number of open slots in a PLC rack.In addition, Mr. Ashmore sees requests for specialized modules like thermocouple, strain gage, and motion control increasing.

"One of the key trends in I/O subsystems is a wider availability of unbundled products, like distributed 'rack,' 'block,' and 'direct' (sensor/actuator) I/O devices that are mated to alternative 'brains,' such as a personal computer," notes Trayton Jay of Mitsubishi Electric Automation Inc. (Vernon Hills, Ill.). " 'Open' standards promote inter-vendor product compatibility.This allows customers to keep the advantages of compact, rugged PLC I/O modules where appropriate and to access [what some perceive as] more open, flexible, or advanced programming and integration environments."

Higher density means wiring woes

Mr. Ashmore calls the "biggest contradiction in customer requests" the fact that customers want more I/O points in a smaller card with the ability to switch higher energy.