EMERSONOvation®-based Digital Rod Position Indication Upgrade

Ovation®-based Digital Rod 

Position Indication Upgrade 

Background

Westinghouse’s digital rod position indication 

(DRPI) display system has been the backbone 

of the DRPI architecture for over 40 years.

Since the original design, advancements in 

technology have created the opportunity for 

the addition of helpful maintenance utilities, 

outage tools, system error detection and data 

logging.

The Ovation®

-based DRPI upgrade display 

system accomplishes the following functions:

• Maintains the function of the original 

design

• Utilizes new advanced algorithm to 

calculate rod position that minimizes some 

critical alarm conditions

• Replaces original display cabinet with two 

large LCDs to display rod position data from 

the Ovation highway

• Provides alarm outputs for deviations 

between measured rod positions within the 

same bank

• Generates system alarm when an error 

(detector shorts, loss or open circuit, gray 

code errors, half-accuracy or power supply 

failure) is detected

Description

The Ovation-based DRPI upgrade replaces 

the electronics portion of the original DRPI 

system display cabinet in Westinghouse plants. 

It communicates with both data cabinets to 

provide the most up-to-date rod position and 

alarm information to the control room, Ovation 

highway and plant computer.

This upgrade will include two standard Ovationbased cabinets and two large LCD displays with 

computer interfaces to the Ovation network. 

The first standard Ovation cabinet is the DRPI 

Ovation cabinet, which replaces the functionality 

of the original DRPI display cabinet. The second 

standard Ovation cabinet is the Ovation server cabinet, 

which provides the Ovation support architecture for 

the DRPI Ovation system along with future upgrades. 

The DRPI Ovation cabinet includes new cabling that 

connects to the existing DRPI field cabling located in 

the control room. This cabinet consists of two data 

interface cards, Ovation controllers and I/O hardware, 

and power supplies. Rod position information from 

both data cabinets is transferred to the Ovation 

controller through the data interface card and Ovation 

I/O modules.

Benefits

The benefits of this upgrade include:

• Reliable indication of rod position

• New position algorithms to improve rod position

• Hot swappable redundant DRPI power supplies

• Ovation support architecture, which reduces cost 

for future Ovation upgrades

• Automatic error logging