Hi SwapnilBhole
I'm going to assume you are using POE devices for factory floor. If 3 devices are connected to the same network (via a router or other DHCP server), the devices will have separate IPs. If there is no DHCP server, you would need to set them to static IPs to make them accessible at the same time.
You can run multiple devices using multithreading approach: https://docs.luxonis.com/software/depthai/multi-device-setup/ - luxonis/depthai-experimentsblob/master/gen2-multiple-devices/main.py
Thanks,
Jaka