Technical data

C
Programming Parameters for DSSI Devices
This appendix describes the console mode procedures for setting and examining
parameters for DSSI devices.
Note
Before you reprogram DSSI devices, you should have a good
understanding of DSSI architecture and VAXcluster software
operation. If you do not have that understanding, you should read
the VMS manuals listed in Appendix A or call your Digital service
representative.
On the VAX 4000 Model 100A system, a DSSI daughter card (KFDDA–AA)
provides two DSSI interface adapters between the KA52 CPU and the DSSI
storage devices.
Each of the two adapters on the KFDDA-AA daughter card provides a DSSI
bus that can support up to eight nodes, where the adapter and each DSSI
storage device counts as one node, hence each DSSI adpater can support up to
seven DSSI storage devices (six DSSI storage devices for a two-system DSSI
VAXcluster; five DSSI storage devices for a three-system DSSI VAXcluster
configuration). The adapters make a connection between the CPU and the
requested device on their respective DSSI bus. Each DSSI device has its
own controller and server that contain the intelligence and logic necessary to
control data transfers over the DSSI bus.
Programming Parameters for DSSI Devices C–1