Bedienungsanleitung Yamaha A3000 (Seite 332 von 376) (Englisch)

48718

332

Zoom out

Zoom in

Vorherige Seite

1/376

Nächste Seite

Connecting external SCSI devices

330

Appendix

SCSI connects a 220-ohm resistance between Vcc and the data lines, and 330-ohms

between the ground and data lines. Termination is achieved when this collective resist-

ance is connected to line 18 of the SCSI bus. Normally, the Vcc signal is output from

line 38 of the SCSI bus to supply the power. If the drive itself has a terminator, the drive

will supply power to the terminator. In this case, it is not necessary to supply Vcc power

to line 38. In general, it is necessary to provide termination at the beginning and the

end of the SCSI bus. This is because termination allows high-speed data transfer unaf-

fected by noise, and keeps the bus signals clean.

■ Realities of terminator installation

Although we have said that a terminator is required at the beginning and end of the

SCSI bus, this is a general principle and not a requirement. For example if the bus is

extremely short (45 cm or less), there are cases in which it is best for there to be a

terminator only on one or the other end. This is something which you should be aware

of when using recent ultra-miniature drives. However if other drives are connected in

addition to these drives, the situation will again be different.

Also, if the SCSI devices are separated by more than 3 meters, it is said that using a

terminator at the 3 meter point is preferable. In this case, three or more terminators

will exist within the SCSI bus.

In this way, the theory and practice of SCSI connections can differ widely. Simply changing

a drive in a system that had been working correctly can cause operation to become

unreliable, or adding a drive to an unreliable system can cause it to start working cor-

rectly. In practice, a certain amount of trial and error is necessary.

■ Reasons for SCSI errors

A SCSI bus operates stably only if all the connected SCSI devices are operating cor-

rectly. If any of the devices are producing noise, the other devices will also produce

errors, and in the worst case, the boot block of a drive can be destroyed. (All data in that

drive will be lost.)

Also, there are cases in which a system on which data appears to have saved may not

have actually saved the data, resulting in data loss.

The following paragraphs will discuss the reasons for such errors, and will provide a

sequence for your troubleshooting.

• Check the SCSI ID

Make sure that there is no conflict between the SCSI ID of each SCSI device includ-

ing the A3000. When shipped from the factory, the A3000’s SCSI ID is set to 6. We

suggest that the internal hard disk normally be set to 4. Be sure to turn off the power

before changing the SCSI ID setting.

• Check the terminator

As discussed above, check the location where the terminator is attached.

Missbrauch melden von Frage und/oder Antwort

Libble nimmt den Missbrauch seiner Dienste sehr ernst. Wir setzen uns dafür ein, derartige Missbrauchsfälle gemäß den Gesetzen Ihres Heimatlandes zu behandeln. Wenn Sie eine Meldung übermitteln, überprüfen wir Ihre Informationen und ergreifen entsprechende Maßnahmen. Wir melden uns nur dann wieder bei Ihnen, wenn wir weitere Einzelheiten wissen müssen oder weitere Informationen für Sie haben.

Yamaha A3000 Seite 332

Brauchen Sie Hilfe? Stellen Sie Ihre Frage.

Missbrauch melden von Frage und/oder Antwort

Art des Missbrauchs:

Forenregeln

Neu registrieren

Andere Handbücher von Yamaha A3000

Das Handbuch wird per E-Mail gesendet. Überprüfen Sie ihre E-Mail.

Ihre Frage wurde zu diesem Forum hinzugefügt

Info