ERP-Scale requires a unique RFC destination for each installation. Every PC where ERP-Scale is installed needs its own RFC destination. Multiple devices (scales) connected to the same PC can share one RFC destination.
The RFC destination is created using transaction SM59 or SAP menu Tools>Administration>Network>RFC destinations.
This section covers how to create SAP RFC destinations.
The Program ID must be unique
A separate RFC destination must be created for every PC where ERP-Scale is installed
explains the relationship between the settings in SM59, HUPAST_C and ERP-Scale.
Security settings in SAP might prevent external RFC connections to the SAP host. See here
for further information.