For HL7 routers/processes, you can use either E=D (On errors disable the component) or E=S (On errors suspend the message and move to the next message. Your choice will depend on whether you want the message flow to stop and address the issue on the spot or if you want the message flow to continue and address the issue at a later time. 

For HL7 operations which I think is what you are asking. You can use :?R=R,:?E=R,E=R,X=R. In this case your operation will retry sending the message when you receive AR, CR (?R=R), AE, CE (?E=R) in MSA:1 response message or error status returned from message handler (E=R) or there is not reply message at all (X=R). You can also add a D after the R to make the operation to be disabled after retrying. However, if the Failure Timeout setting is set to -1 the operation will retry indefinitely, which most likely if what you want. I am sure your sales engineer could provide more inside into this topic.