gtps2m3m | ACF/SNA Data Communications Reference |
TPF supports the following SNA communication trace functions:
The TPF operating system traces monitor supervisor calls (SVCs) and input/output (I/O) interrupts. These traces produce a detailed image of the environment at the time the interrupt occurred. For more information about the realtime trace (RTT), see the TPF Program Development Support Reference.
The path information unit (PIU) trace facility provides a detailed trace of the data transferred between the TPF system and remote resources. See Appendix D, Using the Path Information Unit (PIU) Trace Facility for more information about the PIU trace facility.
The SNA I/O trace facility provides a detailed I/O trace for SNA I/O interrupts that occur during Network Control Program (NCP) XID exchanges, adjacent link station (ALS) XID exchanges, and channel-to-channel (CTC) XID exchanges. Information about significant steps in XID7 processing for CTC devices is also logged in this table. It also provides a detailed I/O trace for NCP, ALS, and CTC asynchronous interrupts. Normal data transfer operations and attention-only interrupts that occur during NCP and ALS data transfer operations are not traced.
The I/O interrupts and the asynchronous interrupts are stored in a 4K-byte table that operates in wrap-around mode. This SNA I/O trace table contains header data and a maximum of 63 entries. Each entry in the trace table has a length of 64 bytes, which includes one byte that is used for status information. The following data is stored in the SNA I/O trace table entries:
The SNA I/O trace facility is initially active for each device defined in the symbolic device address table (SDAT). The SDAT is part of the SNA keypoint that is defined by the CK2SN data macro.
To display the contents of the SNA I/O trace table online, issue the ZDDCA command using the XID dump tag. The SNA I/O trace table is also included in system error dumps that have the control program keyword (ICP) specified in the dump override table. For more information about the XID dump tag and the dump override table, see the TPF Program Development Support Reference. For more information about the ZDDCA command, see TPF Operations.