To unload data from SalesForce, you must first load the file model using the "IKM Salesforce to File", and then use this file model as a source for your interface. This IKM comes in two versions, depending on whether data filtering is required on Salesforce of not. Note that filters executed in SalesForce should be coded in Sforce Object Query Language (SOQL), and not in plain SQL.
Note: SalesForce IKMs uses the AppExchange Data Loader component to load data from and to SalesForce. It should be installed in the machine running the sessions integrating data from and to SalesForce. You should also provide this utility location in the KM options.
Knowledge Modules Reference Guide