This type of detector...
...sent its signal to the dispatchers room. Before a train crossed the detector, the next home signal was coded to STOP. The detector signal was shown to the dispatcher, who had to read it, on a rolling paper in the form much like a seismic graph. He would be counting spikes representing axles, watching for spikes on the graph that were say two times higher than the others. After he read the graph, if there were no high spikes/defects, he would allow the train to proceed. If there were defects he would count how far back they were and let you know. This was always an estimate and you had to check five ahead of and five behind the axle/axles given (this is also true today with the computerized radio transmissions).
I think the dragging equipment detector set off an alarm in the office and you were instructed to stop immediately.
