This transaction is used for manual sending of service order from SAP ERP backend to FSM Cloud.
Please note that in a normal case sending service order is an automatic process triggered by changes in transactions IW31/32.
Strating from the 2202 Release the additional option Send Service Call only has been added. It allows to send Service Call without any related objects (such as address, tasks etc) that are send along with service order in a usual case.