This discussion of the electronic control of the changeable message sign system focuses on the operational strategy, the imput sources, the sign control console, the computer system, and system maintenance. The Traffic Surveillance Computer (Xerox Sigma V) provides electronic detection based on sensors embedded in the pavement at 1/2 mile intervals. The operator has a Datapoint 3300 Cathode Ray Tube display. Each sign consists of 32 matrix type character modules formatted in two rows of 16 characters each. Standard voice grade telephone lines are used to activate the sign from a remote control center. A Data General Model 1220 Nova mini-computer provides the electronic brains at the control center. The hardware and software interfaces between the Nova 1220 and the Xerox Sigma V. A useful tool for trouble shooting the system is the Digicon 300 Field Controller. The details required for timely and accurate sign displays are best provided by ground mounted TV cameras.

Media Info

  • Pagination: p. 96-105
  • Serial:
    • Issue Number: 59

Subject/Index Terms

Filing Info

  • Accession Number: 00129920
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 14 1976 12:00AM