As the machine travels from front to rear, we are using 2 counters to count the transitions of the wheel scrub photoeye X20. C1 increments when the tires are seen. Once it counts two tires, C1 will turn on. This counter has a debounce timer to ignore pulses in between the tires where the guide rails are intended to be installed. At the second pulse, this will start the various decel timers at the rear of the vehicle including foam bath, Trifoam, etc. During the same front to rear pass, C28 is also monitoring the wheel scrub photoeyes. After two pulses, C28 will turn on. C28 basically indicates that the photoeyes are working properly for the next cycle when the machine starts to travel forward. If these two timers don’t increment, the machine will continue to travel to the rear endstops (which you indicate is happening).
At the rear endstops, M246 will turn on. As the machine begins traveling forward, we are monitoring for a single block of the photoeye (to pulse C28). If this pulse occurs, M246 will reset which will allow the front arms to come in on the sides of the vehicle. If C28 doesn’t count, M246 will not reset and will drive all the way to the front of the vehicle with the front arms OUT. If this happens and M246 does not reset, the machine will tag a code of 1480 indicating front arms behind vehicle.
It is normal that the input for the ultrasonics will stay on and occasionally flicker. The ultrasonics are used to determine the type of vehicle washed, but are not part of determining the vehicle length.
In a brush cycle, the rear arm proxes are used to find the rear of the vehicle as they transition from "OFF" to "ON" to "OFF" as they work around the corners of the vehicle.
