An advanced signal design testing and simulation tool


2022 PR Readers Choice Awards Winner

SATS: An advanced signal design testing and simulation tool

The Right Testing System for PTC

Positive Train Control (PTC) has placed a premium on communications and signaling testing, as microprocessor-based software systems have increased in scale and complexity, and rendered traditional, highly manual testing processes insufficient. Princeton Consultants developed the Signal Application Testing System (SATS), a robust simulation tool that improves and substantially automates rail system testing. SATS is now the preferred testing solution for hundreds of engineers, managers and designers.



Improved Testing Accuracy

SATS automates many tests and finds errors that may have been missed during manual assessment. SATS users find 80% or more of software errors during simulation.

Reduced Field Time

SATS users find most errors in the office, not in the field, and they quickly locate problem areas. Testing an entire cutover of project at once is straightforward, saving valuable time.

Defined Processes, Enabled Scale Up

With SATS, test managers instill defined processes, and better manage a growing software portfolio.

Simplified, Accelerated Training

Through display of aspect progression, demonstrated train movement, and logic equation structure, SATS enables new or inexperienced signal engineers to quickly understand a signal system. Typically, new hires are performing simulation testing within two weeks of being hired.

Prompt, Expert Support

Princeton Consultants’ SATS team responds promptly to user questions about the software—and to broader issues about PTC communications and signaling.



  • 5 Class I Railroads 
  • Multiple short lines, passenger and transit operators 
  • A majority of the leading North American signal design and engineering organizations 


  • Simulation support for Alstom and Ansaldo equipment
  • Display of PTC codes, device offsets, rule names and rule numbers
  • Easy import and setup, can begin testing in less than 15 minutes for most locations
    • Automatic asset and route detection
    • Automatic remote link connections between chassis
    • Automatic creation of Local and Office control panels
    • Quick user editable variable assignments to support non-standard nomenclature
    • Connect multiple locations together with simple click-and-drag connections
    • Merge multiple saved SATS files linking several locations together into one SATS file
  • No limits on number of locations supported in a single file, allowing for simulations of entire cutovers (or more) at once
  • Automated testing including creation of aspect tables and running downgrade tests
  • Automated test sheet generation
  • Training mode with automated train(s) to aid in testing and to illustrate the workings of the signaling system
  • ATCS support to test office to field communication

Who We Are

Princeton Consultants blends software development, data science and management consulting to help railroads and other transportation companies improve asset utilization and operational effectiveness. Founded in 1981, we have partnered with Class I railroads on some of the industry’s most challenging initiatives. SATS is one example of our trailblazing work in the following areas:

Positive Train Control

  • PTC communications tools and on-board management systems
  • Systems integration, best-practice operational processes consulting, and disaster recovery/business continuity

Communications & Signals

  • Custom software solutions to improve process accuracy
  • Systems management design and implementation

Load Planning

  • Train planning system development, based on proprietary optimization technology

Rail Car Fleet Management

  • Operational systems development and process improvement to manage