The test request message forces a heartbeat from the opposing application. The test request message checks sequence numbers or verifies communication line status. The opposite application responds to the Test Request with a Heartbeat (35=0) containing the TestReqID <112>.
The TestReqID verifies that the opposite application is generating the heartbeat as the result of Test Request and not a normal timeout. The opposite application includes the TestReqID in the resulting Heartbeat. Any string can be used as the TestReqID (one suggestion is to use a timestamp string).
|Component Block - <StandardHeader>||Y||MsgType = 1|
|Component Block - <StandardTrailer>||Y|
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