Yes, I just managed to get this to work. 

Basically, Outsystems offers out of the box RFC connector to SAP RFCs. You need to make sure that your networking is setup properly. So if you have your Outsystems on-Prem, it should be no issue. If you have your Outsystems in the cloud, you need to enable private vpn tunnel: 

https://success.outsystems.com/Support/Enterprise_Customers/Maintenance_and_Operations/Set_Up_a_VPN_to_your_OutSystems_Cloud

Also check the documentation.