I recently found this model with the ID 'HW-0519' on it. It can be found online (HW-0519 in Aliexpress) and is sold for the purpose of converting UART to RS485 communication using Arduino devices. The MAX485 module (MAX485 in Banggood) is the more commonly used module for this purpose and has been used in many projects. The MAX485 has the following pins DI (data in), RO (receiver out), DE (Data Enable), RE (Receiver Enable), VCC, GND and the 'A' and 'B' pins for the RS485 device (Shown below).
The HW-0519 module, has a slightly different pin configuration, and I can't seem to wrap my head around it. It has Tx and Rx pins, which I am guessing match up with RO and DI respectively, but don't have enable pins. They have the VCC and GND pins along with the 'A' and 'B' pins, but also come with this pin marked in Chinese. I translated it using Google translate and it translates to something similar to 'Ground'. Which is not connected to the GND pin though (Shown below).
Does anyone know whether I can use the HW-0519 module in the same manner as the MAX485? If so, are there any libraries written for this module? I want to use the module for communication with a pH sensor like the one in this link.