But the problem is each sensor modules are not connected with each other. They are seperate module with controllers and attached on the shelves. So all the modules must run at a same time. And it's not possible to synchronise all the sensors because there are many independents modules and wirelessly attached. Basically, it's a pick to light system.
Actually it's the part of my master thesis. Could you please guide me what should I do?
Actually it's the part of my master thesis.
It is paper system project right now but have designed a prototype model for testing. But it will be implemented by company in future if it works successfully.
Have a separate sensor that is used just to receive ultrasonic signals, a read only sensor. You know when your object sensor has fired, the read sensor can then be used to detect residual signals and when the residuals fall below a certain level fire the next sensor.