A Data element is a unit of EDI data. Forexample sender ID and receiver ID are data elements.

Each EDI standard contains a set of data elements specific to thatstandard. These data elements are stored in a data dictionary thatprovides the following information about each data element:

• Name of the element
• Description of the element
• Data type: numeric alphanumeric or date
• Minimum length of the element
• Maximum length of the element
• Element type: fixed-length or variable-length

  Fixed-length data is a type ofdata element or segment with a specific number of characters. Forexample a company name data element might have a fixed length of35 characters.

  Variable-lengthdata is a type of data element or segment with no fixed numberof characters. For example a sender ID data element can be one tofifteen characters in length.

  A Dataelement separator is placed before each data element in a segmentto mark the beginning of that data element. Without data element separatorsan EDI translator does not know where one variable-length data elementends and another begins.

Data element separators must be defined in the EDI data format.When defining a data element separator select a character that isnot likely to appear in the data. This will help prevent translationerrors that might occur during processing. Common data element separatorsare the asterisk (*) used in the ANSI X12 standard and the plussign (+) used in the UN/EDIFACT and TRADACOMS standards.

An EDI standard specifies where a data element appears in a segment.If a data element contains information the information is displayedbetween the data element separators. If a data element does not containinformation there is only a space between the data element separators.If the last data element in a segment does not contain informationnothing appears for that data element.

The following figure shows a data segment that has four data elementsseparated by asterisk (*) data element separators. However thereis no data for the third of the four data elements which is shownby two consecutive asterisks.

Composite Data Elements

A composite dataelement is a data element made up of smaller units called sub-elements.A sub-element separator character such as a colon (:) marks thebeginning of the sub-element.

For example ITEMNO is a dataelement in a purchase order. ITEMNO consists of three sub-elementsthe part number an aisle number and a bin number. If part number345 is located in aisle 9 bin location G the data element ITEMNOoutput would be 345:9:G.

The following figure shows a compositedata element with a colon (:) sub-element separator: