The SCSI Log Sense command
is used to obtain current data from log pages
in a SCSI target
device. The CDB
structure for the Log Sense command is:
The special parameter fields in the CDB have the following meaning:
- PPC - Parameter Pointer Control - if this is one then the target returns a log page with parameter code values which have changed since the last Log Select command or Log Sense command. If PPC is zero then all bytes are returned.
- SP - Save Parameters - if this is one then the target should save all saveable log parameters to a non-volatile memory or media area.
- PC - Page Control - this indicates which type of values should be returned:
- 00 - Current Threshold Values
- 01 - Current Cumulative Values
- 10 - Default Threshold Values
- 11 - Default Cumulative Values
- Parameter Pointer indicates the first parameter code to be returned.
- Allocation Length in bytes
If the Parameter Pointer is zero and the PPC is zero and the Allocation Length is high enough then all parameters are returned.