Interchange Definition

V1.4 30 SEP 2004

An interchange can be defined as a "communication between partners in the form of a structured set of messages and service segments starting with an interchange control header and ending with an interchange control trailer".

NOTE: For use with the Integrated Cargo System and interchange may not exceed 10MB in size.

In other words an interchange has three characteristics:

• it is sent from one party to one (or more) other parties as a complete set;
• it is a structured set of messages in the UN/EDIFACT format which are separated by the defined service segments; and
• it starts with the service segment interchange control header (UNB) and ends with the service segment interchange control trailer (UNZ).

The overall structure of an interchange can be depicted as follows:

		UNA- Service String Advice (Conditional)
		UNB - Interchange Header (Mandatory)
Service Segments
		UNH - Message Header (Mandatory)
Data Segments		Data Segments as defined in message directory
		UNT - Message Trailer (Mandatory)
Service Segments
		UNZ - Interchange Trailer (Mandatory)

 

Interchange Service Segments

This section defines those interchange service segments that are used in the ICS. Please note that the specific message service segments of UNH (Message Header) and UNT (Message Trailer) are defined for each message used in the ICS and are detailed in the section concerning that message. 

UNS Section Separator

The UNS segment is defined as a service segment used to separate Header, Detail and Summary sections of a message, where necessary, to avoid ambiguities in the message segment content. This segment contains one data element. When used to delimit the header section from the detail section, it contains the value "D", and when used to delimit the detail section from the summary section, it contains the value "S". Where the UNS segment is required in an ICS message its usage is defined in the section concerning that message.

 

UNA Service String Advice

The function of the UNA segment is to define the characters selected for use as delimiters and indicators in the rest of the interchange that follows.

Tthe UNA Service String Advice has a mandatory fixed length of 9 characters. The first three characters are UNA, immediately followed by the six characters that will replace the standard delimiters and indicators in the rest of the interchange.

The ICS uses EDIFACT version 3 syntax rules and hence the inclusion of the UNA segment in EDI interchanges is mandatory to ensure full compliance with the EDIFACT standard.

Consequently Customs adds the UNA segment to all outgoing EDI interchanges.

Customs accept incoming interchanges with or without UNA segment. Customs has decided not to make UNA segments mandatory for industry interchanges at this stage. It is recommended that software developers include the UNA segment in all interchanges as development schedules allow. Customs will make UNA segments mandatory at some point in the future, preferably after all software developers have introduced the change.

This segment is made up of 'UNA' followed by the six characters below.

Element	Format	Value
COMPONENT DATA ELEMENT SEPARATOR	M an..1	:
DATA ELEMENT SEPARATOR	M an..1	+
DECIMAL NOTATION	M an..1	.
RELEASE INDICATOR	M an..1	?
REPETITION SEPARATOR (NOT USED)	M an..1
SEGMENT TERMINATOR	M an..1	‘

 

 

UNICSA Interchange Control Structure - (CTLSET)
 

Introduction: 
 
The Service String Advice, UNA, and the service segments UNB to UNZ shall appear in the below stated order in an interchange. 
 
Notes: 
 

v2.2 (7 November 2002)

Pos.

Seg.

Req.

Group

Notes and

No.

ID

Name

Des.

Max.Use

Repeat

Comments

M

0005

UNA

Service String Advice

M

1

M

0010

UNB

Interchange Header

M

1

M

0050

UNZ

Interchange Trailer

M

1

---

	Segment:			UNA Service String Advice
	Position:			0005
	Group:
	Level:			0
	Usage:			Mandatory
	Max Use:			1

 
Data Element Summary 

	Data	Component
	Element	Element	Name	Attributes
M	0101		COMPONENT DATA ELEMENT SEPARATOR	M	1	an1
M	0102		DATA ELEMENT SEPARATOR	M	1	an1
M	0103		DECIMAL MARK	M	1	an1
M	0104		RELEASE CHARACTER	M	1	an1
M	0105		RESERVED FOR FUTURE USE	M	1	an1
M	0106		SEGMENT TERMINATOR	M	1	an1

---

Segment:	UNB Interchange Header
Position:	0010
Group:
Level:	0
Usage:	Mandatory
Max Use:	1

 
Data Element Summary 

	Data	Component
	Element	Element	Name	Attributes
M	S001		SYNTAX IDENTIFIER	M	1
M		0001	Syntax identifier	M		a4
			UNOC    UN/ECE level C
M		0002	Syntax version number	M		n1
			3
M	S002		INTERCHANGE SENDER	M	1
M		0004	Sender identification	M		an..35
			Interchange Creator
X		0007	Partner identification code qualifier	C		an..4
		0008	Address for reverse routing	C		an..14
			Interchange Owner
M	S003		INTERCHANGE RECIPIENT	M	1
M		0010	Recipient identification	M		an..35
			Interchange Recipient Identification
X		0007	Partner identification code qualifier	C		an..4
X		0014	Routing address	C		an..14
M	S004		DATE AND TIME OF PREPARATION	M	1
M		0017	Date of preparation	M		n6
			Transmission Date
M		0019	Time of preparation	M		n4
			Transmission Time
M	0020		INTERCHANGE CONTROL REFERENCE	M	1	an..14
			Interchange Control Reference Number
X	S005		RECIPIENTS REFERENCE PASSWORD	C	1
X		0022	Recipient reference/password	M		an..14
X		0025	Recipient reference/password qualifier	C		an2
X	0026		APPLICATION REFERENCE	C	1	an..14
X	0029		PROCESSING PRIORITY CODE	C	1	a1
	0031		ACKNOWLEDGEMENT REQUEST	C	1	n1
			1    Requested
X	0032		COMMUNICATIONS AGREEMENT ID	C	1	an..35
	0035		TEST INDICATOR	C	1	n1
			1    Interchange is a test

---

Segment:	UNZ Interchange Trailer
Position:	0050
Group:
Level:	0
Usage:	Mandatory
Max Use:	1

 
Data Element Summary 

	Data	Component
	Element	Element	Name	Attributes
M	0036		INTERCHANGE CONTROL COUNT	M	1	n..6
			Interchange Message Count
M	0020		INTERCHANGE CONTROL REFERENCE	M	1	an..14
			Interchange Control Reference Number

	CTLSET (D.99B.UNICSA)						November 10, 2002