ISA segment

The ISA segment is the first segment in an ANSI X12 Interchange. The ISA segment contains data that identifies trading partners. This segment also specifies the delimiters and terminator within the interchange. The segment does not tell you which X12 version data is contained in the interchange. This version information is in the GS segment, which is discussed in the "Funct'lGroup Sub-tree" section.

The type ISA has an Inbound and an Outbound subtype, each of which has a Partner subtype. The Inbound ISA type is used as a component of the Inbound Interchange type. The Outbound ISA type is used as a component of the Outbound Interchange type.

The second component of ISA is the type ISAPartnerInfo which has the following components:

Auth'nInfoQual'r Element
Auth'nInfo Element
SecurityInfoQual'r Element
SecurityInfo Element
Sender InterchangeIDQual'r Element
InterchangeSenderID Element
Reciever InterchangeIDQual'r Element
InterchangeRcv'rID Element
InterchangeDate Element

The following is an example of ISA segment data:

ISA*00*TSI       *01*92511930  *01*ME             *12*BRADLEY        
*970815*1732*U*00201*000000050*0*T*>

It should be noted that this ISA example wraps around on the page, but there is no CL/LF in the ISA segment.

In the data of an ISA segment, the first thing after the initiator ISA is the element delimiter, so the first component of the ISA type is Element Delimiter. The value of the delimiter can be any of a number of different values. In input data, after the delimiter value is found as the first component of the ISA, it is set as the delimiter value for the rest of segments in the entire interchange. Likewise, the Composite Delimiter is the third component of the ISA, and the terminator is defined as the last component of the ISA.

When mapping from EDI data, the syntax values can be mapped from the components of the ISA in the input. When mapping to EDI data, you can set the syntax values by assigning values to the components of the ISA.

Note: The default value for the delimiter is an asterisk *, and the default value for the terminator is a carriage return/linefeed <CR><LF>. If you want to test inbound data that does not contain the interchange envelope, the data must contain the default delimiter and terminator values, or the data will be invalid. If the delimiter and terminator are different from the defaults, change the defaults in your type tree.

The IEA segment is the last segment in an interchange. The IEA segment has the same interchange control number that is in the ISA. The IEA segment also has a count of the functional groups within the interchange.