Abstract: A system of communicating vehicle detection is provided. The system may include a probe having at least a probe controller and a magnetic sensor for detecting the Earth's magnetic fields, and a control system having a main controller, an output port and a two-wire interface for communicating with the probe. The probe controller may be configured to quantify detected magnetic fields into a sensor output value per iteration at a predefined frequency, and initiate an interrupt per iteration the sensor output value is determined to exceed a predefined sensor value. The main controller of the control system may be configured to communicate a supply signal to the probe over a first line of the two-wire interface, monitor a return signal from the probe over a second line of the two-wire interface for interrupts, and generate a call signal on the output port indicative of confirmed vehicle detection if the number of consecutive interrupts in the return signal exceed a predefined interrupt limit.

Abstract: A system of communicating vehicle detection is provided. The system may include a probe having at least a probe controller and a magnetic sensor for detecting the Earth's magnetic fields, and a control system having a main controller, an output port and a two-wire interface for communicating with the probe. The probe controller may be configured to quantify detected magnetic fields into a sensor output value per iteration at a predefined frequency, and initiate an interrupt per iteration the sensor output value is determined to exceed a predefined sensor value. The main controller of the control system may be configured to communicate a supply signal to the probe over a first line of the two-wire interface, monitor a return signal from the probe over a second line of the two-wire interface for interrupts, and generate a call signal on the output port indicative of confirmed vehicle detection if the number of consecutive interrupts in the return signal exceed a predefined interrupt limit.

Abstract: A technique for operating a vehicle detection system involves obtaining samples randomly from a detector of the vehicle detection system and determining the presence of a vehicle in response to the random samples. When multiple detectors are located in close proximity to each other, the likelihood of interference caused by concurrent sampling events is reduced because of the randomness of the sampling, which in turn reduces the occurrence of incorrect vehicle detection results. Control systems for vehicle detection systems obtain the random samples independently from each other. Because the random samples are obtained independently from each other, multiple inductive loop vehicle detection systems can be operated in close proximity to each other without having to be coordinated or synchronized in any way. The possibility of an incorrect vehicle detection as a result of concurrent sampling events can be further reduced using validity checking techniques.