The SAP RFC server receives the IDocs and places these into the JMS topic. One IDoc type results to one topic.
If the embedded JMS broker is used, the topics are not visible. To check what data is stored and to see if messages are received from SAP or consumed by the Job, you need to configure an SAP RFC server that uses an external JMS broker.
The topics are named TALEND.IDOCS.<IDoc Type>. These are set by the consuming Job and the <IDoc Type> that matches the type configured in the tSAPIDocReceiver component.
#Enable/disable RFC trace (1=on or 0=off) jco.server.trace=1
The following shows you that a .trc file is written to the top-level directory: