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. 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 ⚠

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.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. 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.

USB to RS485 is known for its multi-drop characteristics, which means it can be used for connecting multiple RS485 devices in a two-wire network. USB to RS422 is often used for extending a RS232 wire by using a USB to RS422 adapter at each end of a RS232 wire. 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 Thoughts Many of these OEM device boards also have jumper settings or software that can change the mode between RS-232/RS-422/RS-485. The USB to RS485 Converter / USB to RS422 Converter (for USB to RS485 Serial Adapters - Coolgear - Buy the Top USB to RS485 Devices Online) Note: DMX software tutorials are not included here due to paucity of space, thus you need to spend enough time learning more about them!Note: The 120Ω resistor is only required if the module is the first or last device in a multi-drop RS-485 system, to meet RS-485 termination requirements. So, you may need to remove it in certain situations.