LINKMED® Interface Tutorial: HL7 ADT Segments and Fields

6.1    MSH-Message Segment Header

The MSH segment defines the intent, source, destination, and some specifics of the syntax of a message.

Seq
Element Name
Req
 
Len
Comments

0

Segment ID (MSH)

R

3

"MSH"

1

Field Separator (FS)

R

1

This is used to identify separator char  “|”

2

Encoding Characters

R

4

 ^ ~ \ &

3

Sending Application (SA)

O

15

 

4

Sending Facility (SF)

O

20

 

5

Receiving Application (RA)

O

15

 

6

Receiving Facility (RF)

O

20

 

7

Date/Time of Message (TOM)

O

15

YYYYMMDDhhmm[ss]

8

Security (SEC)

O

40

 

9

Message Type (MT)

R

7

ADT – Admit, Discharge, Transfer Message

ACK – General Acknowledgment Message

10

Message Control ID (MCID)

R

20

 

11

Processing ID (PID)

R

1

P

12

Version ID (VID)

R

8

HL7 standard version being used. 
HL7 2.x Version

13

Sequence Number (SEQ)

O

15

 

14

Continuation Pointer

O

180

 

15

Accept Acknowledgment Type

O

2

AL

16

Application Acknowledgment Type

O

2

AL

17
County Code
O
2
 
18
CharacterSet
O
 
6
 
19
PrincipalLanguageOfMessage
O
 
60
 
20
AlternateCharacterSetHandlingScheme
O
 
20
 
21
MessageProfileIdentifier
O
 
250
 

R = Required, CR = Conditionally Required, O = Optional, N = Numeric, AN = Alpha/Numeric, ID = Segment Identification

 

6.2 MSA-Message Acknowledgment Segment

The MSA acknowledges receipt of incoming messages.

Seq
Element Name
Req
 
Len
Comments

0

Segment ID (MSA)

R

3

"MSA"

1

Acknowledgment Code (AC)

O

2

AA, AE or AR

2

Message Control ID (MCID)

R

20

ID of the message from the sending system (MSH_10)

3

Text Message  (TM)

O

80

LINKMED® TCP/IP NAK Text Message

4

Expected Sequence Number (ESN)

O

15

 

5

Delayed Acknowledgment Type (DAT)

O

1

 

6
Error Condition
O
100
 

R = Required, CR = Conditionally Required, O = Optional, N = Numeric, AN = Alpha/Numeric, ID = Segment Identification

Optional HL7 Segments for ACK/NAK= SFT and UAC uses only with HL7 version 2.6 and above


| HL7 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 |