DDS for display files
The 3270 remote attachment feature allows a 3270 SNA controller or a 3274
emulating device to be attached to an iSeries server.
Some applications for the 3270 that use data description specifications
(DDS) may require programming changes. An operator at a 3277, 3278, or
3279 data entry keyboard can use most features and functions as a similarly
configured and authorized 5250 workstation. The attached unit has the
same capabilities and limitations as any remote 5251, with the following
exceptions:
- No display attributes are seen on either a 3278 or a 3279 when the field
is defined as a non-display field.
- Numeric-only fields that are used for negative numbers act differently on
the 3270 than on the 5250. On the 3270, if the operator enters a
negative number in the field, the sign occupies the first position of the
field followed by the number. This causes the maximum size of the field
to decrease by 1 and should be considered when designing the displays and
fields.
- Results that cannot be predicted can occur when data is entered in an
input field that is involved in a page command, if any lines involved in the
page are not of the same type field attributes and location.
- The following DDS keywords are ignored by 3270 support:
- AUTO (RA) and CHECK (ER)
- BLINK (cursor blink is controlled by keyboard for 3270)
- CHRID
- CHANGE
- LOWER or CHECK (LC) (lowercase is controlled by switch on display for
3270)
- CHECK (RL and RLTB)
- DSPSIZ (other than 24 x 80)
- LOCK
- MSGLOC (set to row 24)
- Note:
- For display devices configured as a 3278 Model 4, the MSGLOC keyword is set
to display messages on row 43.
- The following DDS display attributes are the only ones valid for 3270
Remote Attachment (except for 3277):
- DSPATR
- RI used for 3278 and 3279 CS used for 3278 and 3279 (changed to UL) UL
used for 3278 and 3279 BL used for 3278 (determines color on 3279)
- During a write operation to the error line, the Enter key is defined as a
Reset key and cannot be mapped to any other function.
In addition, if a write operation is requested by the user application to
display an error message, a read operation should immediately follow the write
operation for the remote 3270 display to allow resetting of the error
message. A read operation following a write operation of an error
message should be used by call applications regardless of the type of target
display. If a read operation does not immediately follow the write
error message requested by the user application, remote 3270 displays may
overlay the error message before it can be read by the user.
[ Top of Page | Previous Page | Next Page | Table of Contents | Index ]
(C) Copyright IBM Corporation 1992, 2005. All Rights Reserved.