This article explores ARC family sensors, particularly the Hamilton ARC analytical sensor, for industrial network communication using the Modbus RTU protocol. It emphasizes the sensors' ability to act as servers, eliminating the need for transmitters, and details the use of VP8 cables for sensor connections. The author discusses Hamilton Process Analytics' wireless solutions, including a Bluetooth adapter, and introduces their motivation to develop a Wi-Fi/Modbus RTU communication gateway using the ESP32 for a Hamilton ARC pH analytical sensor. The article includes a code snippet for the ESP32 gateway, highlighting its low hardware cost but the demand for programming expertise. In conclusion, the ESP32 is suggested as a promising gateway option for smaller-scale or budget-conscious applications in the Industrial Internet of Things (IIoT) landscape.