This introduction aims at addressing the basic questions of convention and implementation of the EDI technology.  I have a list of topics, and hope that over time I can cover all of them.  I also hope that people reading here may have questions that I haven’t thought to write about.  Please let  me know what your questions are and I will see what I can do about providing answers.

• What is EDI?
• Parts of EDI
• Segments
• Delimiters
• Conventions of EDI
• Why are there more than one version of EDI?
• Standards and Usage
• Encoded Values
• EDI in Good Form
• Element Notation
• Wrapped and Unwrapped EDI
• Enveloping Part One
• Enveloping Part Two – ISA
  
• Enveloping Part Three – GS
• Enveloping Part Four – ST
• Loops in EDI
• Hierarchical Levels

Of course understanding how EDI presents and represents data is the first step.  From here we may want to go to our Data Mapping Guide, or if we are familiar with mapping there are some examples in our mapping case studies of EDI to and from other formats.  Again, if you have an interesting problem or solution, I would love to here about it.  Please send it to
roy@TheIntegrationEngineer.com and I will see what I can do.

The ISA Segment is the first segment in any EDI document.  Once you understand what it is saying, This long random seeming string will make sense, and be very helpful in helping you relate EDI documents to the real world task that you need to do.

Here is an ISA segment.

ISA^00^          ^00^          ^01^9012345720000  ^01^9088877320000  ^080902^1523^U^00401^000000001^0^T^|~

This is one long string, there is no linefeed or line break.

Like all segments, the first element is 0 and identifies the segment type.  This is an ISA segment.

There are 16 ISA elements, here are the definition for the ISA

A note on Qualifiers

A qualifier is an element that precedes an element and defines the type of data will be found in the element that it precedes.  The Qualifier element is also an encoded element.  Encoded elements are elements that have a defined set of possible values.

The Unit Of Measure is my favorite example of a qualifier.  The UOM precedes the quantity.  Thus when you have a quantity of 5, your will know that it is 5 boxes not five containers or eaches by knowing what the UOM qualifier is for that quantity.  For the Unit Of Measure, there is a specific set of them and what they mean.

Element by Element

ISA_01 is a qualifier.  The Authorization Information Qualifier can be one of 7 values from 00 to 06.  Most of the time it is 00 which means that ISA_02 will not contain meaningful data.  This field must be populated with one of these values.

ISA_02 is for Authorization Information.  If the ISA_01 is 00, this will normally be left blank.  If ISA_01 is one of the other 6 valid values, this field must be populated.  The value here will be used to determine the authorization of the document.  I have only seen this used with one trading partner.  You might not see this at all.

ISA_03 is also a Qualifier.  It is the Security Information Qualifier and can be one of two values, 00 or 01.  Most of the time it is 00 which means that ISA_04 contains no password.  This field must be populated with one of these values.

ISA_04 is for Security Information.  This is also called the password.  If the ISA_03 is 01, this must contain a value.  Most of the time this will be blank.

ISA_05 is an Interchange ID Qualifier.  There are two of these.  They qualify or define the Interchange ID field that they precede.  These are required to be present.  There are 41 valid options, and I won’t define them all here.  Some common usages are:

01 = DUNS number

12 = Phone number

14 = Duns Number with Suffix

16 = DUNS with 4 character suffix

ZZ = mutually defined.

ISA_06 is the Sender’s Interchange Identifier.  This value will identify the sender to the receiver.  The receiver should have this as a unique value.  Thus some times it is necessary to have more than one option in case the value you have chosen is already in used by some other Trading Partner that the receiver exchanges documents with.

ISA_07 is an Interchange ID Qualifier.  It follows the same rule as ISA_05 but qualifies the receiver instead of the sender.

ISA_08 is the Receiver’s Interchange Identifier.  This values tells the sender’s system where the message is going, and tells the receiver’s system that this message is for them.  The sender will need to have a unique value for each trading partner.

ISA_09 is the Interchange date.  This is the date that the ISA envelope is created.  Sometimes this value is derived from the contents of the document, but ideally this should be the date of the interchange envelope.

ISA_10 is the interchange time.  This is the time that the ISA envelope is created. Sometimes this values is derived from the document, or is defaulted to midnight.  Ideally this should be the time of the interchange envelope.

ISA_11 is the Standard Identifier.  This will always be ‘U’ identifying this as the US EDI standard.

ISA_12 is the Standard Version Number.  This relates to the major version of the EDI standard that is used.  This value needs to be accurate so that the receiver’s EDI system can expect the right size of fields in the GS segments.  This may not look like what it is, as you see this ‘00401′ for a version of ‘4010′.  This only identifies the major version, not distinguishing between 4010, 4011 and 4012.

ISA_13 is the Interchange control number.  This is the way that an EDI system identifies the envelope.  This control number should not be random, but an incrementing number.  It is 9 digits padded with zeroes.  The combination of ISA Sender and Receiver Identifiers and the Control number should identify a distinct interchange transmission.  When 9 ‘9’s are reached, the control number should roll back to 1. Nine zeros should be avoided as some systems that may internally trim the zeros will them be presented with a null value.

ISA_14 is the Acknowledgment Request.  This lets the EDI file make a request for a functional acknowledgment or 997 to be transmitted. This is a binary option of 0 meaning “don’t send a 997.”  and 1 meaning “send a 997.”  In a perfect world any ISA with a 1 in this would get a 997 returned.  In the real world, most EDI systems require some setup to enable the 997, thus it is good to discuss this before sending the request.

ISA_15 is the usage indicator.  This can be one of three values.  P is for Production Data, T is for Test Data, and I is for Information Definition.  This is important as a EDI system should only process interchanges with the P as production data.

ISA_16 are the delimiters.  You may remember from the delimiter discussion that these are in a fixed position.

Too Much?

Really there are only a few things that you need to worry about as you start working with EDI and the ISA.  If you are just needing to do a quick edit for a test or to resubmit a document, here is what is important.

• Pay attention to the ISA_05, 06, 07 and 08.  These are the sender and receiver fields.
• Increment you control numbers to make sure that you EDI files don’t get booted as dupes.
• Make sure the ISA and IEA have matching control numbers.

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There’s more!  Now we explain the GS envelope.

For an overview of Enveloping go here.

Looking for the ST enveloping page?

Looking for something else relating to EDI?  Check out the EDI Primer post