25.4 Envelope definition - Standards for electronic data interchange within the UK Blood Transfusion Services

The envelope definition defines the content of the first and last lines of the file/transmission (see Table 25.1 and Table 25.2).

The first or header line contains an identifier specifying that this is a message complying with a UKBTS specification, the date and time generated, the source and destination of the message, and the protocol number which identifies the relevant protocol to which the message conforms.

Source and destination identifiers for the Blood Establishments will be the ISBT 128 collection facility identification code. It is anticipated that hospital blood banks will use the identifier assigned by their local Blood Establishment.

The terminator line contains a record count indicating the total number of message lines excluding the header and terminator lines, and a standard terminator message.

Table 25.1: Envelope definition - header line
Field Length Description Format Mandatory?
1
5
Line number
NNNNN (see note 1)
Yes
2
10
Fixed text
‘UKBTSSTART’
Yes
3
8
Date
YYYYMMDD
Yes
4
4
Time
HHMM
Yes
5
6
Protocol number
NNNNNN (see note 2)
Yes
6
6
Source ID
XXXXXX
Yes
7
6
Destination ID
XXXXXX
Yes
8
2
Checksum
NN
Yes
9
1
Terminator
Carriage return
Yes

Notes on Table 25.1

  1. Always 00001 for header line.
  2. Allocated by the Standing Advisory Committee on Information Technology (SACIT).
Table 25.2: Envelope definition - footer line
Field Length Description Format Mandatory?
1
5
Line number
NNNNN
Yes
2
9
Fixed text
‘UKBTSSTOP’
Yes
3
5
Number of records
NNNNN
Yes
4
2
Checksum
NN
Yes
5
1
Terminator
Carriage return
Yes

Last updated on 15 July 2013