The following figures provide a summary of the cabling guidelines.

The following figures provide a summary of the cabling guidelines.

System

Non-Sun device

Sun device

Autoterminating

Sun device

68 - 68

68 - 68

68 - 68

System

Sun device

Autoterminating Sun device

50-pin device

 

 

 

 

 

 

 

 

 

T

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Terminator

68 - 68

68 - 68

68 -50

 

 

 

 

Adapter cable

Multi-initiator Support

The SCSI implementation of the system includes multi-initiator support: any external host adapter on the bus can drive Termpower. This means that if the system should lose power, the devices on the SCSI bus (except those powered by the system) can continue to operate.

Configuration Rules

For fast/wide performance, you can connect up to 12 devices to the external SCSI bus. For UltraSCSI performance, no more than seven devices may be connected. Each device must have a unique target address (SCSI ID) in the range from 0 to 15.

You cannot assign target address 7 to any device; it is reserved for the host adapter on the main logic board.

For UltraSCSI performance on the external SCSI bus, all cables used must be UltraSCSI-compliant, and you must adhere to the following bus length restrictions:

For 1 to 3 devices, the maximum bus length is 3 meters (9.84 feet)

For 4 to 7 devices, the maximum bus length is 1.5 meters (4.92 feet)

86 Sun Enterprise 220R Server Owner’s Guide • October 1999

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Image 114
Sun Microsystems 220R manual Multi-initiator Support, Configuration Rules