Tip 4000: Scsi Interface; Table 3-3. Scsi Device/Bus Types: Precautions - StorageTek L700 Service Manual

TIP 4000: SCSI Interface

TIP 4000: SCSI Interface
Use this TIP if the client system does not recognize the library.
Before starting, be sure that the SCSI cables are the correct type and length for your
operation. SCSI cable information is covered in
CAUTION:
Compatibility problem: The single-ended, differential, and LVD/SE
alternatives are not compatible and cannot be mixed on the same SCSI
bus.
You can use the "Lib SCSI I/F Config" menu from the operator panel to check the valid
SCSI bus connections. The screen that displays the SCSI ID of the library will display
either "single-ended" or "differential."
If the screen displays "invalid," you have mixed single-ended devices with differential
devices somewhere on the bus. The table below lists possible symptoms of mismatched
bus types.

Table 3-3. SCSI Device/Bus Types: Precautions

If you plug a . . .
Single-ended device
Low voltage
differential device
High voltage
differential device
Correct the bus connection, then use the menu to verify the bus connection.
Symptom Explanation
The library cannot be accessed by the
client system.
3-12
Into . . . The result is . . .
Single-ended bus Proper connection
LVD bus Single-ended mode
HVD bus Operation disabled
Single-ended bus Single-ended mode
LVD bus Proper connection
HVD Potential damage/disabled device
Single-ended bus Disabled device
LVD bus Potential damage/disabled device
HVD bus Proper connection
Conditions That Could Cause This Symptom
• The system is not working or incorrectly configured
• Incorrect library configuration
• Loose or incorrect cable connection at the system or at
the library
• Defective MPC/MPCL card
Fourteenth Edition
StorageTek Proprietary
Table 1-3 on page 1-5.
95846