There may be tens of thousands of street lamps in the streets and along the highways. To inspect each lamp to check if it is working is an arduous task. Isn't it nice to have a system, which will automatically report if a lamp in a Public Lighting System has broken down? The infrastructure required of such self-reporting function must be very complicated and the cost prohibitively high. Not if you use ARCHNET power line modems.
       The ARCHNET power line modem makes use of the power cable as a communication medium and data communication can take place between two points on a power line without the need of a dedicated signal wires. An ARCHNET power line modem and a sensor connected at the power source of the street lamp of a public lighting system can sense the current flow through the lamp, thus monitoring the operation of the street lamp. If the lamp breaks down, the modem will report the address code of the lamp report back to the monitoring station through the power cable. At the Public Lighting control station, a signal will flash on the screen giving the location of the street lamp. A repairman can then be sent immediately to the right location to check and replace the bulb.
       Using the PLC Modem, the Public Lighting Control Center can send a command to operate the On/ Off relay of a particular street lamp over the power line to turn on or off that street lamp in a public lighting system. Similarly, the Public Lighting Control Center can broadcast an On/ Off command at fixed times over the power line to operate street lamps in different zones of a Public Lighting System.