The component is used to create the RSS Limited barcode symbols. It's defined in the pRssLimited unit.
RSS Limited is a continuous linear symbology capable encoding the entire GS1 14-digit EAN.UCC item identification number (Global Trade Item Numbers, GTINs) set with Indicator digits 1 and 0. The first digit represents the Indicator digit to indicate packaging level (only 0 and 1). The following twelve digits are the GS1 Company Prefix and the Item Reference. The last digit represents the Check Digit. A leading Application Identifier (01) is implied and is not encoded in the symbol.
Normally, the overall size of the RSS Limited symbol is 74 modules wide by a minimum of 10 modules high.
If both the Link2D and Show2DSeparator properties are set to Ture, a contiguous separator pattern is represented and its minimum height is 1 module (the pattern height can be specified by the SeparatorRowHeight property). In this case, the height of the RSS Limited symbol will be reached to increase the contiguous separator pattern height. Namely, If height of the contiguous separator pattern is 1 module, then the minimum height of the RSS Limited symbol is 11 modules.
The TotalHeight property can be used to specify the height for an RSS Limited symbol, in modules. If the contiguous separator pattern is represented, its height is included in the property value.
No quiet zones is required outside the bounds of the RSS Limited symbol. The first and last elements may appear wider than one module without affecting the symbol if the adjacent background area is the same color. So the minimum values of LeadingQuietZone, TrailingQuietZone, TopQuietZone, and BottomQuietZone properties are equal to 0.
The RSS Limited symbols have a check digit, it is a form of redundancy check used for error detection. It consists of a single numeric character computed from the other character in the EAN.UCC item identification number.
If the AutoCheckDigit property is set to false, the check digit shall be included in the barcode text. Otherwise, It wii be appended automatically by the component, so the check digit isn't required in the barcode text.
The RSS Limited symbology encodes the entire GS1 14-digit EAN.UCC item identification number (Global Trade Item Numbers, GTINs) set with Indicator digits 1 and 0 in a symbol, including a leading indicator digit (only 0 and 1), 12 data characters (GS1 Company Prefix and the Item Reference), and a Check digit. Note, A leading Application Identifier (01) is implied and is not encoded in the symbol, so it isn't required in the barcode text.
Note, First numeric character is the Indicator digit in the barcode text, only 1 and 0 can be encoded.
If the AutoCheckDigit property is set to false, the check digit shall be included in the barcode text, so the length of barcode text shall is 14 numeric characters, and the last numeric character in the barcode text is the check digit.
If the AutoCheckDigit property is set to true, the check digit will be appended automatically by the component, so the length of barcode text shall is 13 numeric characters, and the check digit isn't required in the barcode text.
The RSS Limited barcode symbol can be used together with a 3-column CC-A or a 3-column CC-B barcode symbol to create the EAN.UCC composite symbol.
If you use it together with a CC-A or a CC-B component that's from another components package, the Link2D property should be set to true in order to denote the RSS Limited symbol is used as the linear component in an EAN.UCC composite symbol. In this case, the Show2DSeparator property specifies whether to represent the contiguous separator pattern between the RSS Limited linear and the 2D components in the EAN.UCC composite symbol.
If you use it together with the TBarcode2D_CCA or TBarcode2D_CCB 2D barcode component that's in this 2D Barcode VCL Components package, it can be used as the Linear property's value of the 2D barcode component to create the EAN.UCC composite symbols. In such case, only the Barcode, Data (only for Delphi/C++ Builder 2009 or later), AutoCheckDigit, TotalHeight, and SeparatorRowHeight properties are useful, the value of other properties will be ignored and they will be set automatically depending on the settings of the 2D barcode component (the Link2D and Show2DSeparator properties will be set to true automatically). The number of columns of the TBarcode2D_CCA or TBarcode2D_CCB 2D barcode component will be changed to 3 automatically. In addition, the Image property should not be normally set, the Image property's value of the 2D component will be used.
See also the "How to generate the EAN.UCC composite barcode symbol".
See diagram:
(*): The Data property, OnInvalidDataLength and OnInvalidDataChar events are available only for the Delphi/C++ Builder 2009 or later.