Hi Susan,
I am sure that we can extract data to a non sap system from any datasource.
Currently I am working on integration of SAP with Informatica and we are using only datasources to extract our data and even these work in parallel extractions with SAP BW and Informatica both.
So I would suggest that you contact your basis team to establish the connectivity between the systems.
For starters, try below:
1. Check RFC connections in SM59.
2. Activate the datasource again in RSA5,LBWE etc.
3. Fill Setup tables.
4. Check ALE communication and partner settings in WE21/20 etc.
5. Check table RSBASIDOC if there is a logical system entry for your non sap system.
6. Ensure saprfc.ini file entries are correct on your non sap system
Ideally you should not have any errors if you have the correct communication settings between the ECC and non sap system.
Let me know your findings.
Thanks
Amit