Laying out a design where a solder jumper is used to enable the TE feature.
When the TE is not HIGH, can it just be left unconnected?
The resistor is effectively connected across the receiver input pins by setting TE high and disconnected when TE is LOW or the device is UNPOWERED. Rugged 3.3V RS485/RS422 Transceivers with Integrated Switchable Termination | Analog Devices Since it's controlled by logic, I do recommend setting it low as per the table in the datasheet for the performance to be predictable. I don't recommend floating it. It is a "Logic-Selectable" 120Ω Termination Resistor after all.