Are they compatible for software bin file and hardware interface? Thanks!
101-1051 was an old part number. So they are both the same part.
My recollection is that the “20-” prefix was used to indicate RoHS-compliant products around 20 years ago. So 20-101-1051 is the current part number for the RCM3365, and as far as software is concerned both parts will appear identical.