Is an external termination resistor required for the USB2-H-500X-M USB to RS485 adapters?
Answer:
Termination resistors are often used at each end of an RS485 link to prevent reflections of the signals. The USB2-H-500X-M USB to RS485 adapters include built-in 120 ohm termination resistors which can be enabled and disabled easily via a DIP switch. This avoids the need to have external termination resistors. The manual has details of the DIP switch settings for each model USB2-H-500X-M Family Datasheet.