MSS1 and MSS2 records

MSS1 and MSS2 records are created as a result of ABORT processing when an I/O error (correctable or not) occurs. All available control blocks are snapped, regardless of any trace options in effect on the link involved.

These records are followed by a type X'03' record containing the message that was sent to the master terminal as a result of the error.

The following table shows the significant control blocks snapped in MSS1 and MSS2 records.

Table 1. Significant fields in MSS1 and MSS2 records
Link type Control blocks
CTC

POST code (first word of LLB)
DECTYPE
LLB, LTB(S), LCB, LXB, CRB, CTT, LNB control blocks
IOSB
MSCWA (MSC work area)
I_WP_BUF, O_WP_BUF

I/O buffers (input and output). In non-bandwidth mode, the I/O buffers include I_TP_BUF and O_TP_BUF. In bandwidth mode, the input and output I/O buffers include:

  • I_BUFHDR, O_BUFHDR Send and receive buffer headers
  • BUFRSP Response data
  • BUFMSG Message data
  • BUFERR Error message data
  • BUFRST Restart data
  • BUFQUI Shutdown data
  • BUFUNK Unknown data
MTM

POST code (first word of LLB)
DECTYPE
LLB, LTB(S), LCB, LXB, CRB, CTT, LNB control blocks
MSCWA (MSC work area)
I_WP_BUF, O_WP_BUF

I/O buffers (input and output). In non-bandwidth mode, the I/O buffers include I_TP_BUF and O_TP_BUF. In bandwidth mode, the input and output I/O buffers include:

  • I_BUFHDR, O_BUFHDR Send and receive buffer headers
  • BUFRSP Response data
  • BUFMSG Message data
  • BUFERR Error message data
  • BUFRST Restart data
  • BUFQUI Shutdown data
  • BUFUNK Unknown data
TCP/IP

POST code (first word of LLB)
LLB, LTB(S), LCB, LXB, CRB, CTT, LNB control blocks
MSCWA (MSC work area)
I_WP_BUF, O_WP_BUF
SCIWORK (SCI work area)

I/O buffers (input and output). In non-bandwidth mode, the I/O buffers include I_TP_BUF and O_TP_BUF. In bandwidth mode, the input and output I/O buffers include:

  • I_BUFHDR, O_BUFHDR Send and receive buffer headers
  • BUFRSP Response data
  • BUFMSG Message data
  • BUFERR Error message data
  • BUFRST Restart data
  • BUFQUI Shutdown data
  • BUFUNK Unknown data

DFSAWE, the input AWE from the CSL SCI Input message exit. This AWE chain is initially queued to the LXBAWEHDR, then moved over to CLBQE by the TCPIP post handler DFSTCP20 for processing by the DDM. The AWE is mapped by the DFSAWEXI macro. The AWXI_MBRPLPTR field contains the DFSMSDIR parameter list from SCI.

DFSMSDIR, the parameter list of doubleword parameters, containing the length and address of the parameters that are passed between MSC and IMS Connect through the SCI interface.

ICONDATA, the data from IMS Connect, pointed to by the DFSMSDIR parameter MDIR_ICONMSGPTR. This data is mapped by the BUFMS macro, starting at BUFMSHDR.
VTAM®

POST code (first word of LLB)
LLB, LTB(S), LCB, LXB, CRB, CTT, LNB control blocks
MSCWA (MSC work area)
I_WP_BUF, O_WP_BUF
RPLs (request parameter list)

I/O buffers (input and output). In non-bandwidth mode, the I/O buffers include I_TP_BUF and O_TP_BUF. In bandwidth mode, the input and output I/O buffers include:

  • I_BUFHDR, O_BUFHDR Send and receive buffer headers
  • BUFRSP Response data
  • BUFMSG Message data
  • BUFERR Error message data
  • BUFRST Restart data
  • BUFQUI Shutdown data
  • BUFUNK Unknown data