Part 4.9 Loop

What is a Loop?
Loops are a group of two or more related segments that repeat.

What are the types in Loops?

• Bounded explicit loops.
• Unbounded implicit loops.
• Hierarchical explicit nested loops.

What is a Bounded loop?

• Bounded or explicit loops are identified with segments that specify the beginning and end of looping structure in the data.

What is an Unbounded loop?

• Unbounded or implicit loops are identified by the first segment in the loop and have no special segments for loop definition. 

What do you know about HL segments?

• Hierarchical Level segments indicate parent-child relationships among occurrences.
• HL segments identify dependencies of hierarchical level data.
• HL segments identify explicit nested loops within a transaction.

Mention the elements in the HL segment.

• HL01 – ID Number (Usually “HL Counter”)
• HL02 - Parent ID (HL01)
• HL03 – Level Code (Identifies Level)
• HL04 – Child Code (0 = no children, 1 = children)

The requirement of valid EDI file (ANSI X12)

List of requirements -

• The first line will start with three letters: “ISA”.
• ISA 13th element should match with IEA 2nd element.
• ISA Segment’s length is 106 bytes with 16 Elements.
• The second line will start with "GS”.
• GS 6th element should match with GE 2nd element.
• GS Segment’s length is 24 bytes with 8 Elements.
• The third line will start with "ST”.
• ST 2nd element should match with SE 2nd element.
• The header and trailer controller number will be the same.
• The number of the segment between ST & SE, including ST, & SE will have to match with the SE 1st elements. 
• The number of the Functional Group (GS/GE) will have to match with IEA 1st Element.
• The number of Functional Groups can be maximum up to 99999 times with same Functional Group ID in an Interchange Envelope.
• The number of Transaction Sets can be maximum up to 99999 times with same Transaction Set ID in a Functional Group.