The OT Discovery scan struggles to detect SNMP-enabled Schneider Modicon PLCs, as it fails to retrieve SNMP data. To work around this, I have to manually change the asset type from OT to another category, scan it using Lansweeper on-prem to capture the SNMP information, and then revert it back to OT. I also manually select Modbus and SNMP protocol in the scan. I didn't test it on device with SNMP v3 as there is no place for me to enter the credentials information. In the Network Discovery Hub website, there is also a location where I can enter the manual SNMP v3 credentials in the Discovery section, however it is a onetime scan and doesn't retain the information. It also doesn't work.
Additionally, the scan does not retrieve details about the backplane or its attached modules.
OT Network Discovery version 4.2.5