Unable to communicate with a deice over rs485
You are showing that the Arduino will be using a single supply for the 485 voltage levels.  Many RS232 and 485 devices are based on dual supplies and would not be compatible with your single sided scheme.  Check whether the device uses a dual supply.  If there is +/- 5 or 12 V on the transciever, then it may not Rx with your Arduino Tx.

I'm presuming you are using 10x probes but have not set the scope scale.  Those voltages are low even with 10x.  Second consider what signal voltage levels your device expects. I have not seen serial devices operating other than +/- 12V