HLLP

The HLLP envelope consists of a Start of Block component, a ”D’ (Data) or ”N’ (NAK) indicator, an HL7 Version component, a Carriage Return, a Data component, a Block Size component, a Block Checksum component, an End of Data component, and an End of Block component. The size of the HL7 Data field is determined by the length of the data (number of bytes between start and end), with a maximum size of 99999 Bytes.