In developing a control system, there are many functions that need to be considered for inclusion. The most important in almost all applications is the nature of the graphical interface, that is, how the operator will interface with the process/operation over which the control system is functioning.

In addition to a range of pure graphical interface requirements, most applications, regardless of industry, also need a standard set of functions, such as data logging, trending, alarm management, and report generation. These functions so closely ally with the graphical interface function that they are generally assumed as an integral part of the basic interface. Beyond these basics, use of specialized functions varies greatly among different industries and other applications for which the user must determine the need.

Ideally, in all system implementations, a full requirements set will be determined and agreed upon prior to software selection and implementation. Unfortunately this does not occur in many applications. Often, the developer must contend with changing and escalating requirements for the system. Even with good upfront definition, many systems installed for one purpose, end up doing more for the enterprise during their life cycle.

GE Fanuc (Charlottesville, Va.) offers a flexible software product, Cimplicity HMI, which provides an incremental approach to HMI functionality. Because it is offered as a modular package, users can purchase the degree of system functionality required for their application. Additional features can be added as required. Modularity also allows economical use of one software tool across a range of applications for which a developer may be responsible.

The basic package provides a wide range of common functions, including graphics, alarm management, communication drivers, and trending. Its graphics editor supports a large library of standard (some very detailed) objects. These can be placed and sized as required onto a graphic, as well as ActiveX objects and objects from other applications.

However, using the graphics editor was somewhat cumbersome-the ability to zoom in is fixed to a set of percentages. My personal preference for graphics editing is to be able to zoom to a window that can be framed as required.

The system does include a wide list of communication protocols that expands its use beyond GE Fanuc products. Also included in the base offering is the ability to create supervisory control actions in Basic that trigger from data elements in the networked processors. With the range of options available, systems can be made as simple or as complex as required.

Because of the software's scalability, several tiers of database size and major function options are available. Options include statistical process control, recipe management, redundancy, and inventory tracking. It also includes a tool kit that improves the interface to other software packages.

Cimplicity HMI features strong network architecture. Individual controllers or controller networks reside under implementations designated as servers and, then, in true client/server fashion, other machines on the supervisory network can access data in that application. These clients can be other servers or simple data viewing locations.

Finally, user documentation for both the base package and most options is included on the release disk for the base package. This helps configuration of the basic software functions and also aids in evaluating what additional features might add to an application.

This review is based upon Cimplicity HMI, Version 4.01 from GE Fanuc. The software is provided on CD-ROM for use under Windows 95, 98 and NT.

For more information on Cimplicity HMI, Circle 345 or visit www.controleng.com/freeinfo.