Article ID: 159275
Article Last Modified on 11/19/2003
8.1 The TN3270E Message Header
As stated earlier, each data message in TN3270E must be prefixed
by a header, which consists of five bytes and is formatted as
follows:
-----------------------------------------------------------
| DATA-TYPE | REQUEST-FLAG | RESPONSE-FLAG | SEQ-NUMBER |
-----------------------------------------------------------
1 byte 1 byte 1 byte 2 bytes
8.1.1 DATA-TYPE Field
The DATA-TYPE field indicates how the data portion of the message is
to be interpreted by the receiver. Possible values for the DATA-TYPE
field are:
Data-type Name Code Meaning
-------------- ---- ---------------------------------
3270-DATA 0x00 The data portion of the message
contains only the 3270 data stream.
SCS-DATA 0x01 The data portion of the message
contains SNA Character Stream data.
RESPONSE 0x02 The data portion of the message
constitutes device-status information
and the RESPONSE-FLAG field indicates
whether this is a positive or negative
response (see below).
BIND-IMAGE 0x03 The data portion of the message is
the SNA bind image from the session
established between the server and the
host application.
UNBIND 0x04 The data portion of the message is
an Unbind reason code.
NVT-DATA 0x05 The data portion of the message is to
be interpreted as NVT data.
REQUEST 0x06 There is no data portion present in
the message. Only the REQUEST-FLAG
field has any meaning.
SSCP-LU-DATA 0x07 The data portion of the message is
data from the SSCP-LU session.
Additional query words: prodsna
Keywords: kbinfo kbnetwork KB159275