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File: ad00814_
Writer: Terry Cowling

Concept topic

This build: July 31, 2007 21:21:46

TDS format: Tagged separation types

For tagged separation types, each data value is preceded by a tag that is specified as an element property.

The Tag Data Separator, or specific Length of Tag parameter is used to determine where the tag ends and the data starts. Different methods are used by each separation type to determine the end of the data.

After considering these two parameters, this topic describes the following supported tagged separation types:

Tagged separation is a flexible format. The elements do not have to occur in a specific order. They do not all need to be present, and can be absent from any point in the message.

Tag Data Separator and Tag Lengths

Either Tag Data Separator and Length of Tag are used by all tagged separation types. But only one of these parameters can be set at the same time.

The point at which a tag ends and data starts can be determined by one of two methods. If the Tag Data Separator is set, then this character indicates where the data ends. For example, the string might be:
tag1:data1
where Tag Data Separator is :
However if the Tag Data Separator is not set and the Length of Tag field is set, then the tag is the specified length, and is immediately followed by the data. No separating character is required. For example, the string might be:
tag1data1
where Length of Tag is 4

Tagged Delimited separation

Tagged Delimited separation is a completely flexible format. The elements are not of specific lengths. Elements are separated by a predefined delimiter.

Applicable parameters

These parameters are used:
  • Group Indicator indicates the start of a group or complex type.
  • Group Terminator indicates the end of a group or complex type.
  • Delimiter separates the data elements within a group or complex type.
  • Tag for each element, indicates the tag needed to precede the data in that field.
  • Either Tag Data Separator or Tag Length as described above.

Examples

If Tag Data Separator is set to :
{tag1:data1*tag2222222:data2*tag333:data3}
where:
  • Group Indicator is {
  • Group Terminator is }
  • Delimiter is *
  • Tag, defined for each element, is tag1, tag2222222, tag333 respectively
or, for example, if Length of Tag is set to 5
{tag11data1*tag22data2*tag33data3}
where parameters are as above, except:
  • Tag, defined for each element (fixed at 5 characters), is tag11, tag22, tag33 respectively

Tagged Fixed Length separation

Although Tagged Fixed Length separation is a flexible format, the data must be a specific length. This means that a delimiter is not needed to determine the end of each element.

Applicable parameters

These parameters are used:
  • Group Indicator indicates the start of a group or complex type.
  • Group Terminator indicates the end of a group or complex type.
  • Tag for each element, indicates the tag needed to precede the data in that field.
  • Either Length or Length Reference for each element, indicates the length of the data. (This value does not include the length of the tag.)
  • Either Tag Data Separator or Tag Length as described above.

Examples

If Tag Data Separator is set to :
{tag1:data1tag22222222:data2000tag333:data300}
where:
  • Group Indicator is {
  • Group Terminator is }
  • Delimiter is *
  • Tag, defined for each element, is tag1, tag22222222, tag333 respectively
  • Length, defined for each element, is 5, 8, 7 respectively
or, for example, if Length of Tag is set to 5
{tag11data1tag22data2000tag33data300}
where parameters are as above, except:
  • Tag, defined for each element (fixed at 5 characters), is tag11, tag22, tag33 respectively

Tagged Encoded Length separation

This method has both a tag and a length field before the data. The length field indicates to the parser the length of the data following it.

The length of this length field is itself defined in the Length of Encoded Length parameter. Extra lengths to be added in this, such as the length of the field itself, is set in the Extra Chars in Encoded Length parameter.

These examples show how the values set in these parameters are applied:

Applicable parameters

These parameters are used:
  • Group Indicator indicates the start of a group or complex type.
  • Group Terminator indicates the end of a group or complex type.
  • Tag for each element, indicates the tag needed to precede the data in that field.
  • Length of Encoded Length indicates the length of the length field in the bit stream.
  • Extra Chars in Encoded Length indicates how many extra characters should be included in calculating the value for the length field in the bit stream.
  • Either Tag Data Separator or Tag Length as described above.

Examples

If Tag Data Separator is set to :
{tag1111:008data1tag222222222:010data2AAtag3333:009data3A}
where:
  • Group Indicator is {
  • Group Terminator is }
  • Length of Encoded Length is 3
  • Extra Chars in Encoded Length is 3
  • Tag, defined for each element, is tag1111, tag222222222, tag3333 respectively
or, for example, if Length of Tag is set to 5
{tag11008data1tag22010data2AAtag33009data3A}
where parameters are as above, except:
  • Tag, defined for each element (fixed at 5 characters), is tag11, tag22, tag33 respectively
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This build: July 31, 2007 21:21:46

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