Hello Ayman -
To which Input are you referring? At the 10.2.1 product release 'Poll an ArcGIS Server for Features' allows you to choose either the 'FeatureServer' or 'MapServer' endpoint of a published service to poll for feature data. Other product capabilities such as synchronizing GeoFences also support the selection of 'FeatureServer' or 'MapServer' endpoints.
Are you trying to use a 'MapServer' endpoint and it is not working?
- RJ