Hot Backup Redundancy Software

Modern Machine Shop, Oct, 2000 by Elizabeth M. McPhail

The company's new Max-ON hot backup redundancy software delivers an off-the-shelf configuration solution for applications such as fuel loading, standby power generation, boiler systems and manufacturing systems that require a modular level of critical control.

Integrated with standard 90-30 PLCs and a wide range of I/O options, this software family, which includes Max-ON Lite, Max-ON Standard and Max-ON Extended, provides the benefits of a redundant CPU system without program development costs. With a standard plug-and-play approach to subroutines such as synchronization of variables, redundant I/O bus control, program equivalence testing, selection of master CPU and advanced diagnostics, Max-ON reduces the demands on system administration and maintenance personnel.

The redundant portion of a configured system consists of two 90-30 PLCs that communicate with each other and the remote I/O system over Genius LAN. Max-ON's user-friendly environment allows the user to create the configuration by selecting from available point-and-click options. The configuration utility makes extensive use of dialog boxes for entering system configuration information. The Windows-based configuration utility is integrated with the VersaPro application development environment. The VersaPro development environment is then used to apply the software to the redundant processors providing all necessary system communication and synchronization functions.

The software also features diagnostics to facilitate troubleshooting, such as analog input out of range, CPU off-line, loss of I/O block, system bus fault, CPU configuration mismatch and I/O bus failure. Additional benefits of the hot backup redundancy software include factory standard platforms, scalable CPU performance, fault tolerant I/O communications, a variety of HMI communications options and automatic program download.