The school zone flashing beacons in Longview, Texas (pop 85,000) used a paging system to program school signals. Keith Covington, Traffic Signal Supervisor, determined the system “limited us, not only communicating with the clocks but monitoring the clocks”. ELTEC’s SYSTEM 3000 was chosen to centrally program, manage, and monitor each TC-3000 IP time clock (36 total).
After reviewing available communication options to the Traffic Center from each LANG 3000 (gateway), it was determined to use the Water Department’s Ethernet connections. By utilizing three water towers, “reaching all our areas without spending a lot of money and without having a monthly bill” was doable according to Keith.
The water tower Ethernet connection is located at base of each tower. To avoid coax signal loss, LANG 3000’s (enclosed in a small cabinet) were installed on the top of the water towers. CAT 5 cable from the tower base to the top provides power and data communication. Doing so eliminated approximately 100 feet of coax cable ensuring maximum transmit power at the antenna. The 1 watt, 900 MHz spread spectrum radio didn’t lose signal strength by doing it this way.
After installing four gateways, one of the LANGs could not ‘see’ one school’s beacons due to hills and trees. Locating the fourth LANG to an intersection controller cabinet with a fiber connection, enabled them to utilize the system’s repeater capability resolving the problem. Two intermediate clocks were programmed to create and support a communication pathway. According to Keith “by installing the LANG in the intersection controller cabinet in the area of communication difficulty, the redirection of repeating signals (clock to clock) came easy when trying to maintain communication back to the Traffic Center.”
The DLPRO 3000 software is “easy to use and user friendly.” He continues, “Having the capability to connect and monitor each clock individually and quickly determines if lights are flashing with great accuracy. It’s a valuable tool of communication compared to the old system.” Monitoring all clocks at a glance is also an option with the Background Monitor function. With the former paging system, “you couldn’t validate if lights where flashing or not without going directly to the site or someone reporting it.” The SYSTEM 3000 “allows the opportunity to fix problems before they are noticed by the public through the DLPRO 3000 monitoring feature in the software.”