As your CORE HL7 Listeners are running they will automatically create Traffic Log files in the Traffic sub-folder of the Data Folder defined in your Listener Profile(s).
Traffic Log files will be named Traffic.<ID>.<DateStamp>.log and are created daily. If your CORE HL7 Listener does not receive any HL7 messages during that day then no Traffic Log file will be created.
•<ID> is the ID Field defined in your Listener Profile(s)
•<DateStamp> will be the current system date.
Traffic Log files are purged according to the File Maintenance settings in your Global Settings.
The Traffic log is an incredible troubleshooting or auditing resource that you should take advantage of when needed.
Have you ever wondered how many HL7 messages your CORE HL7 Listener received over the course of a given day? Just open the Traffic log for that day and count the lines in the file.
Has a trading partner ever asked if you received a HL7 message? Or claimed that they never got a HL7 ACK for a particular message. You can tell in the Traffic log.

Sample Traffic Log
The Traffic log is a TAB delimited file created daily. In examining the sample log file in the screen-shot above we can tell that on this particular day my CORE HL7 Listener received 387 HL7 messages. I can even take a deeper dive into the data and get more information. The data fields in the traffic log:
1.Time Stamp. Down to the millisecond of when the message was received. It's not a Date-Time stamp because the files are created daily so you always know the date.
2.Message Control ID. This is MSH (10.1) from the message received.
3.Message Type. MSH (9.1)
4.Message Event. MSH (9.2)
5.Sending Application. MSH (3.1)
6.Sending Facility. MSH (4.1)
7.Receiving Application. MSH (5.1)
8.Receiving Facility. MSH (6.1)
9.HL7 Message Date. MSH (7.1)
10. Test/Prod Flag. MSH (11.1)
11. HL7 Version. MSH (12.1)
12. HL7 ACK Type. This is not from the message data but is the type of HL7 ACK which was returned by your CORE HL7 Listener.