MFS bypass for the SLU 2 (3290) with partitioning

For output, the application program must supply the Create Partition data stream within the output message, along with the data for the partitions. Also, the SLU 2 Device-Dependent Module sets Change Direction (CD) on non-last conversational output messages. This allows Reads and Queries to be sent in Write Structured Fields data streams.

A Query Reply input can be processed only if the previous MOD specified is DFS.EDTN. A Query Reply input can be received but does not have a transaction code in the data stream.

For partitions 01 through 0F, the X'88' byte is followed by a 2-byte field that is not used. If a X'80' byte follows this field, then the next byte is the PID byte (X'01' through X'0F'). For partition 00, the input will have the same format as input data from a non-partitioned SLU 2.

For input with DFS.EDT or DFS.EDTN, the first AID byte, X'88', causes the proper decoding of the second AID byte. Depending on the second AID byte, one of the following occurs:

• If the second AID byte decoded is X'80', a third AID byte is decoded. The data stream following that AID byte is passed to the application program as follows:
  • Using basic edit, if DFS.EDT is specified
  • As a complete data stream, if DFS.EDTN is specified
• If the second AID byte is not X'80', input is passed only if the MOD specified in the application is DFS.EDTN. When DFS.EDTN is specified, the complete data stream starting with the X'88' AID byte is passed to the application program.