User`s guide

Contents cliii
Direct Access Self-Defining Parameter
This self-defining parameter provides the ID for use in the destination/origin structured field in the
direct access of the IBM auxiliary device.
This SDP is always required to accompany the base query reply.
Table D-7. IBM Auxiliary Device Direct Access SDP
Offset Length Content Meaning
0 1 byte 0x04 Parameter Length
1 1 byte 0x03 PCLK Protocol Controls
2-3 2 bytes DOID Destination/Origin ID
DOID: The value in these bytes is used in the ID field of the destination/origin structured field to
identify the auxiliary device as the destination or origin of the data which follows.
PCLK Protocol Controls Self-Defining Parameter
The presence of the PCLK Protocol Controls self-defining parameter indicates that the PCLK Protocol
Controls structured field, ID = 0x1013, can be used both inbound and outbound in data streams
destined to or from the IBM auxiliary device processor.
Table D-8. IBM Auxiliary Device PCLK SDP
Offset Length Content Meaning
0 1 byte 0x04 Parameter Length
1 1 byte 0x03 PCLK Protocol Controls
2-3 2 bytes VERS Protocol Version
VERS: The value given in VERS is used to indicate the version of PCLK installed in the terminal at
the time the query reply is returned. For example, 0x000l indicates PCLK version 1.1.
See the IBM 3270 Information Display System Data Stream Programmer’s Reference for the field
definitions for this query reply.