It’s straightforward to convert the RS-485 line to the unbalanced UART interface using a dedicated IC. The simplest solution (as the one discussed here) does have reasonable protection features but is not galvanically-isolated ⚠ Onboard TVS (Transient Voltage Suppressor), effectively suppresses surge voltage and transient spike voltage in the circuit, lightning-proof & anti-electrostatic. An old Freestyler attempt (2018) https://www.codrey.com/electronic-circuits/usb-to-dmx-interface-adapter-converter-v1-0/ Many of these OEM device boards also have jumper settings or software that can change the mode between RS-232/RS-422/RS-485. This is an industrial USB to RS485 converter with original FT232RL inside. It features embedded protection circuits such as lightning-proof, resettable fuse, ESD protection, and TVS diode, etc. It's pretty small in size.

Likewise, in some cases when termination is enabled, unexpected zero bytes can be received at the beginning or end of a message. To resolve this, bias resistors are often added to the Data+ (A) and Data- (B) lines to ensure that the lines go to an idle state when no node is driving data onto the bus. At this point, remember, only one set of bias resistors should only be used on the bus. So, the bias resistors should be removed from the module if another node on the bus is already providing the bias. Unfortunately, this module does not have jumpers for easy switching of the termination and bias resistors 😥 USB to RS-485 Converter – Isolation ThoughtsThe USB to RS485 converter and USB RS422 adapter, otherwise referred to as USB to RS485/ USB RS422 converters, are small electronic devices used for converting USB signals into either RS485 or RS422. Some of these converter/ adapter units are limited to converting USB to either RS485 or USB to RS422 but others have the ability to convert both RS485 and RS422 via a built-in auto-detection function or other manual configuration selection. All units convert bi-directionally which means they all convert data signals in both directions. USB cable problem: Using a poor-quality USB cable or USB plug may cause distortion or interference with the electrical signal, which may lead to automatic disconnection. Use good quality USB cables or USB plugs whenever possible. The USB to RS485 Converter / USB to RS422 Converter (for USB to RS485 Serial Adapters - Coolgear - Buy the Top USB to RS485 Devices Online)

Protection: 600W lightning-proof and surge-suppress, 15KV ESD protection (onboard 120R balancing resistor).These USB to RS485 converters and USB to RS422 adapters are typically used for connecting an RS485 or RS422 device to a personal computer. Since RS485 or RS422 ports are absent from most computers, you can utilize either a USB to RS485 converter or USB to RS422 adapter to interface between your computer and device via the computer’s USB port. There are broad range of OEM companies that make these low cost converter devices that function to convert USB to RS485 and RS422 standards. RS485 and RS422 are communication standards that are suitable for harsh environments where there may be a lot of electrical interference from other devices and machines. These standards are half duplex transmission meaning that the only one communication is being done at a time using 2 wires. Using 4 wires full duplex can be achieved. Keep note, many of the users did not like the idea of using a converter without galvanic-isolation especially in an industrial environment.

Note: Try to keep the RS-485 bus as short as possible because long wires may add extra interference. You can use regular cat5e networking cable for the wiring but after twisting the A and B wires, it is not very crucial.DMXControl 3 http://wiki-en.dmxcontrol-projects.org/index.php?title=Getting_started_with_DMXControl_3 Power supply problems: The power supply for the FT232 must be stable; an insufficient or unstable power supply may cause automatic disconnection. Make sure the power supply you use can provide enough current and the voltage is stable. Please replace the USB port, USB 3.0 port is recommended, or try a different computer. RS-485 Half Duplex Serial Adapter The USB-8COMi-M allows you to add 8 USB to RS-422 or RS-485 serial ports by connecting to a host USB port. Constructed from… As you can see, the module is a very compact and ready to use piece of electronics. It performs the USB (Universal Serial Bus) to two wire RS485 (Two-Wire Half-Duplex) and vice versa conversion. The module holds an FT232RL USB UART IC with MAX485 to switch between the USB and RS-485 communication standards. Note: DMX software tutorials are not included here due to paucity of space, thus you need to spend enough time learning more about them!