New Product Exclusive: Controllers Are Simply Redundant

RTP's Micro2008V/2016V

Many process control applications require more reliability than typically provided by a standard PLC. Redundant PLCs increase reliability, but these systems have limitations and can be complex to implement. Triple modular redundant (TMR) systems are very reliable but are also very expensive.

RTP Corp.'s new Micro 2008V/2016V redundant hybrid control systems fill the niche between redundant PLCs and TMR systems. They are much less expensive than TMR systems and provide many of the same benefits.

Company officials claim these systems are more reliable, easier to implement, and often less expensive than redundant PLCs. "These are hot standby systems, which means fault recovery is instantaneous. That's not the case with redundant PLCs," says Sal Provanzano, president of RTP.

The Micro 2008V and Micro 2016V are high-integrity voting versions of RTP's existing Micro 2008 and Micro 2016 controllers. Each has two processors, two power supplies, and two backplanes populated with identical I/O. Each processor contains its own 100 MHz Ethernet link to the host network plus an interprocessor Ethernet link.

The two processors (primary and secondary) synchronously execute the application program. The primary processor drives the outputs, communicates with the host, and communicates with other RTP controllers. The secondary instantaneously takes over if the primary fails.

An Ethernet link from each processor to the host provides network redundancy. The secondary processor also takes over if the primary processor encounters communication problems with the host.

For I/O redundancy, each processor resides in its own chassis with identically configured I/O cards connected to the same input and output points. Both the primary and secondary processors scan their own inputs, but only the primary processor drives the control outputs. If a hardware error is detected in the primary's I/O, the secondary takes over as the primary.

Data redundancy is accomplished through comparison of input and output data by each processor during each step of program execution. Each processor sends messages containing measured and computed data to its redundant partner. Each processor then compares its computed values with data received from the other processor, and any discrepancy in these values generates an error message.

"These control systems create a new level of dependable operation for small to medium-sized mission-critical applications," concludes Provanzano. "Our target markets are applications that require hot standby control, redundancy, advanced analog functionality, and high speed."

For more information call 954/974-5500 or see

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