In X12, addressing information is included in both an inner and an outer envelope. The outer envelope begins with an ISA segment and ends with an ISE segment. The inner envelope begins with a GS segment and ends with a GE segment. The message, or transaction, begins with an ST segment and ends with an SE segment.
In EDIFACT, there is always an outer envelope, but an inner envelope is not necessarily used. The outer envelope begins with a UNB segment and ends with a UNZ segment. The inner envelope begins with a UNG segment and ends with a UNE segment. The message begins with a UNH segment and ends with a UNT segment. There is an optional UNA segment that is used only to change the default delimiters.
In HL7, while there are outer and inner envelopes, they are used infrequently. The outer envelope begins with a FHS segment and ends with a FTS segment. The inner envelope begins with a BHS segment and ends with a BTS segment. Instead, addressing information is included in the header and trailer of the message. A message begins with the MSH segment and has no ending segment. (In ECMap, we artificially create an EOT end-of-message segment so that the map flow works correctly.)
The following charts show how the components of each EDI envelope are used by, stored in, or created by ECMap. The following information is shown for each element:
The window and text box in which the value for each element is entered.
The table in the trading partner database in which the information entered in the text boxes on the window is stored and from which it is retrieved.
The system variable into which the information in the databases is loaded and from which the information is obtained.
The envelope structures are presented in the order shown below:
