3270 orders are included in both inbound and outbound data streams
to provide additional control function.
The following table lists the order codes that occur in 3270 data streams,
and shows whether they relate to inbound or outbound data streams, or both.
Table 1. Order codes occurring in 3270 data
streamsOrder code |
Inbound |
Outbound |
Start field (SF) |
Yes |
Yes |
Start field extended (SFE) |
Yes |
Yes |
Set buffer address (SBA) |
Yes |
Yes |
Set attribute (SA) |
Yes |
Yes |
Modify field (MF) |
No |
Yes |
Insert cursor (IC) |
No |
Yes |
Program tab (TB) |
No |
Yes |
Repeat to address (RA) |
No |
Yes |
Erase unprotected to address (EUA) |
No |
Yes |
Graphic escape (GE) |
No |
No |
Note: The
3270 Data Stream Programmer’s Reference states
that the SFE, SA, and MF orders are not supported in ASCII. However, they
do occur in 3270 data streams for the EPI, where they take the following values:
SFE X'10'
SA X'1F'
MF X'1A'
Each of these orders is followed by one or more
attribute type-value pairs. The count of attribute pairs and the attribute
type are both binary values, and are thus as defined in the
3270 Data Stream Programmer’s Reference. However,
the contents of the attribute value field can vary from those defined in the
3270 Data Stream Programmer’s Reference as follows:
- If the attribute type is less than or equal to X'C0' (for example,
a color), the attribute value is defined as an EBCDIC value in the 3270 Data Stream Programmer’s Reference. The
EPI uses the ASCII equivalent of the EBCDIC value; for example, red is defined
as X'F2' in the 3270 Data Stream Programmer’s Reference,
and should be defined as X'32' in the EPI data stream.
- If the attribute type is greater than X'C0' (for example, field
outlining), the attribute value is a binary value. The EPI uses the values
defined in the 3270 Data Stream Programmer’s Reference.
Further details of 3270 orders and other control characters are supplied
in the files named in the following table.
|
Supplied file |
COBOL copybook |
cics3270.cbl |
C header file |
cics3270.h |