Client wanted to simplify user interaction with parking, have full remote control over all devices and data of the entire parking, and also automate entry / exit processes with license plate recognition. We had investigated the idea and designed technical description and project architecture. Then we developed the system according to tasks, where most interesting part was a local server with Modbus protocol. It uses to communicate devices with backend instance. To receive device's data in live mode between frontend and backend applications we used Websockets protocol. This system already works and now we see that we found best solution, because it works with minimal resources for support.