Produttore : Adaptec
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The default termination setting for a channel is Automatic. This setting allows the SCSI card to adjust SCSI termination automatically, depending on which connectors have SCSI devices attached to them. Regardless of the SCSISelect termination setting, the SCSI card termination is always disabled when the power is turned off. If you want SCSI card termination to be enabled when the power is turned off, you must terminate the SCSI channel manually. To manually terminate the channel on the Adaptec SCSI 29320LPE, place a shunt on the Termination enable jumper.The next figure shows where the jumper is located on Adaptec SCSI 29320LPE. Chapter 4: Understanding SCSI . 20 Termination Enable Jumper J4 If you manually terminate the SCSI card with jumpers, you will override the SCSISelect setting. Making changes in SCSISelect will have no effect on termination when these jumpers are installed. You might want to manually terminate the SCSI card if an Adaptec SCSI Card is connected to one or more external SCSI devices that are also connected to a SCSI card in another system. The devices can be shared between the two computers if one SCSI card is terminated when it is powered off, while the system with the other SCSI card is using the SCSI devices. Connecting SCSI Devices Here are some examples of how you can connect internal and external SCSI devices to an Adaptec SCSI Card. Attach the first device to the end connector of the cable (furthest from the SCSI card); attach other devices to the connectors that are closer to the SCSI card. Adaptec SCSI Card 29320LPE Here are some examples of how you can connect internal and external SCSI devices to the Adaptec SCSI 29320LPE card. T T Built-in Terminator on Cable Terminated Device The following figure shows SCSI devices connected to the internal connector. Built-in Terminator on Cable T Chapter 4: Understanding SCSI . 21 The following figure shows SCSI devices connected to the external connector. Terminated Device Maximum Cable Lengths The total length of cabling (internal and external) on the SCSI bus cannot exceed the maximum lengths listed in the following table. The third column lists the maximum number of SCSI devices you can connect to the SCSI card. Maximum Cable Length Data Transfer Rate Maximum Devices Supported 25 m (82.0 ft) Ultra320 SCSI (320 MB/sec) 1 Ultra160 SCSI (160 MB/sec) Ultra2 SCSI (80 MB/sec) 12 m (39.4 ft) Ultra320 SCSI (320 MB/sec)1 15 Ultra160 SCSI (160 MB/sec) Ultra2 SCSI (80 MB/sec) 3 m (9.8 ft) Fast Wide SCSI (20 MB/sec) 15 3 m (9.8 ft) Fast SCSI (10 MB/sec) 7 3 m (9.8 ft) Ultra SCSI (40 MB/sec for 16-bit, 20 MB/sec for 4 8-bit) 1.5 m (4.9 ft) Ultra SCSI (40 MB/sec for 16-bit, 20 MB/sec for 5-72 8-bit) 1 Mixing Fast/Ultra devices with Ultra320/Ultra160 and Ultra2 SCSI devices causes t...