Multiple Function Detectors

The TD250 is designed for ease of installation with front panel switches for setting presence times and sensitivities and operating frequency plus four operating modes.

It provides outputs in the form of LEDs on the faceplate and change-over relay contacts. A common fault relay provides an output in the event of a faulty loop or a power failure.

Two main models are available, both providing the option of  2 separate vehicle presence outputs per channel plus 3 further operating modes:

The TD250D provides: Direction Logic (AB), Delay Mode, Extend Mode

The TD250L provides: Direction Logic (AB), Speed Logic, Headway Logic

An output will be provided when pre-set speed or headway threshold has been exceeded, and can be utilised for switching variable warning signs or for gathering traffic statistics.

features

• Comprehensive diagnostic capabilities allow for accurate diagnosis of loop and installation problems
• The loop isolation transformer provides protection against lightning, transient damage and allows for operation with single point to ground sensor loops
• Visual loop fault monitor helps in localising the fault in the event of a maintenance call-out
• Adjustable Presence time with a choice of four presence output settings
• Direction Logic Option used to establish the direction of vehicle travel with an output provided for each direction
• Delay Mode (TD250D) where a vehicle must be present for a pre‑set time before the detector will operate
• Extend Mode (TD250D) where the detector output responds immediately to a vehicle’s presence and remains for the selected time after a vehicle has departed the loop
• Speed Mode (TD250L) where an output relay provides a pulse output when a pre-set speed threshold has been exceeded
• Headway Mode (TD250L) where each channel independently monitors and measures the interval between vehicles in seconds and provides a pulse output in the event of the vehicle headway being less than the pre-set threshold