GE MEDICAL SYSTEMS CT9800 QUICK SYSTEM
Rev. 14 Direction 18000
4-3-65
CONTROLLER ERROR LOG
The ODC SCSI processor uses an error logging system to save detailed failure related information in a reserved
area of the MDD. The log saves 24 words (48 bytes) of information for each error. The disk space reserved for
this log is limited to six 512 byte sectors beginning at block address 78 Hex on the MDD. Each new error is
placed at the beginning of the log and older entries are pushed down one entry. The layout of each entry is
shown here:
Note: For purposes of troubleshooting, WORD 0 and 1 contain the information needed to isolate a problem.
WORD Upper Byte Lower Byte
0 ERROR CODE
1 SCSI UNIT (0-3 = ODD units; 4 = MDD)
2 Not Used
3 Not Used
4 Not Used
5 DRIVER CONTROL BLOCK OFFSET (for programming purposes)
6
thru A
DESCRIPTOR BYTE 1
DESCRIPTOR BYTE 9
DESCRIPTOR BYTE 0
DESCRIPTOR BYTE 8
B SCSI STATUS BYTE
C INTERFACE ERRORS
D SCSI MESSAGE OUT (Last message to ODD)
E SCSI MESSAGE IN (Last message from ODD)
F INTERFACE STATUS (Status of the SCSI command)
10
thru 17
SENSE BYTE 1
SENSE BYTE 15
SENSE BYTE 0
SENSE BYTE 14
Error Log Entry Layout
DESCRIPTOR BYTES (WORDS 6-A) contain the SCSI command Descriptor for the last drive command
executed. The command descriptors make up either a 6 byte or 10 byte command that is sent from the ODC to
the drive.
SCSI STATUS BYTE (WORD B) the lower byte is the ending status returned from the drive after execution of
the command contained in the Command Descriptor Bytes.
Status = 00 Hex indicates good completion only if bit 7 = 0 to indicate status buffer valid.
Status = 02 Hex indicates “CHECK CONDITION”; upon receiving status, the ODC attempts a Request.
Sense command for further status. Sense information is contained in WORDS 10-17.
To Next Page
Loading...
