Quantum DAT 160 Betriebsanweisung

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Chapter 3  Installing External Tape Drives
Checking SCSI Termination
Quantum DAT 160 User’s Guide
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Why Does the Tape Drive Need a Terminator?
3
Terminators are essential, as they provide the correct voltages on the SCSI 
bus and prevent unwanted signal reflections from interfering with data 
transfers. The rule is:
There must be termination at both physical ends of the bus and only at 
the ends. 
Normally the HBA forms one end of the SCSI bus and provides 
termination. You, therefore, need to ensure that the other end of the bus is 
terminated. If the tape drive is at the end of the SCSI bus, the terminator 
must be attached to the tape drive. 
If you want to attach additional devices to the SCSI bus after the tape 
drive, you will need to remove the SCSI terminator and attach the next 
device to this SCSI connector. Make sure that you attach the terminator to 
the last device in the chain. 
Always use an LVD terminator (supplied with the tape drive) or a 
multimode terminator. See 
 for more 
information about SCSI cables and termination.
Checking SCSI Termination
If the external tape drive is the last or only device in the SCSI chain, install 
a terminating plug on the unused SCSI connector on the drive’s back 
panel. This terminator typically is a small, rectangular plastic block that is 
marked 
SCSI Terminator
 shows two examples of using SCSI 
termination.