Exitech's Simulated NumaC Package Features

EXITECH's Simulated Numac package provides all the functionality needed to meet your training requirements without the need to purchase expensive OEM equipment. The Simulated Numac package consists of a reproduction of the actual Numac hardware along with a display editor used to reproduce the plant Numac feel and functionality while taking advantage of EXITECH’s field proven models.

  • All the functionality (required for training) as contained in the actual GEH Numac used in the control room of a Nuclear Power Plant.
  • Ability to develop custom displays without having to rely on OEMs.
  • Easy integration into existing simulation environments.
  • Uses Ethernet to communicate with host computer rather than RS-232.
  • Display editor has a Test mode built in that allows for debug during display development.
  • Portability for use on a desktop or classroom.
  • The power and flexibility of the real Numac at a fraction of the OEM replacement cost.

Nuclear utilities that replace legacy systems with GEH Numac equipment face the problem of how to cost effectively provide training for this new equipment (both in the classroom and on their full scope simulators).  EXITECH’s simulated Numacs provide a solution to this problem.

EXITECH’s simulated Nuamcs are custom devices incorporating a microprocessor running Linux that communicates with simulation software via Ethernet. A task running on the training computer interfaces the simulation globes with the Numac sending calculated variables to the Numacs and receiving user input from them.

One of the most difficult tasks to perform when simulating equipment like a Numac is the generation of screens that duplicate those of the actual device.  EXITECH’s Numac solution accomplishes this by a provided an offline screen generation/editing program.  The program displays a graphical representation of Numac and allows the user to create displays via an intuitive drag-and-drop interface. Editing the properties of the objects allows for the definition of driving variable, meter scales, alarm Boolean, etc.  The program allows the user to see exactly how the display will look on the simulated Numac. The generated screens are saved in Numac Display Files (.ndf) for use by the simulated Numacs.  

An added benefit of the program is that it can be coupled with the simulation software to allow for debug of the display and simulation software while running without panel hardware.

High Fidelity Models

Hardware alone is not sufficient to accurately simulate the Numac’s functionality.  Also required are high fidelity models.  Some of EXITECH’s field proven models include:

  • Power Range Nutron Monitoring system (PRNM) & Low Power Range Monitoring (LPRM)
  • Average Power Range Monitoring (APRM)
  • Oscillation Power Range Monitoring OPRM
  • Rod Block Monitoring (RBM)
  • Steam Leak Detection system
  • Log Rad Monitoring system


These models have been incorporated into simulators running EXITECH's Chattanooga, GSE's OpenSim, Thunder's ThunderSim and Western's 3KeyMaster. In addition, we have tested these models running in the L3 MAPPS and the OpenSim environments.

Glasstop Implementations

For standalone or glasstop implementations, EXITECH provides a softpanel version of the display generator program.