SCSI Connections

SCSI Restrictions

 

Terminators

 

The terminators for Ultra2 Wide Low-Voltage Differential SCSI (LVD

 

SCSI) and Ultra Narrow Single-Ended SCSI (NSE SCSI) are different.

 

The NSE SCSI terminator has 50 pins and will fit on a NSE SCSI

 

connector. The LVD SCSI terminator has 68 pins and will fit on a LVD

 

SCSI connector. Note that these SCSI terminators were shipped with

 

your system.

 

It is necessary to put a terminator on unused SCSI connectors on the

CAUTION

 

back panel of the system. However, if SCSI devices are attached to the

 

bus via these connectors, the external device connected to the SCSI bus

 

must be terminated with a SCSI terminator. If you do not already have

 

the SCSI terminators, you must order terminator A1658-63012 (for the

 

50-pin terminator; NSE SCSI) or A4986-63008 (for the 68-pin

 

terminator; LVD SCSI) from Hewlett-Packard.

 

 

Number of Devices Per SCSI Bus

The number of SCSI devices per bus is limited (see Table 4-1). Before adding another SCSI device, determine if the system can support the additional device.

This workstation offers the following types of SCSI buses, each with their own configuration constraints:

• Ultra Narrow Single-Ended SCSI bus

• Ultra2 Wide Low-Voltage Differential SCSI bus

Considerations for Selecting SCSI Devices

SCSI devices supported by the Hewlett-Packard Company for the Ultra Narrow Single-Ended (NSE) and Ultra2 Wide Low-Voltage Differential (LVD) SCSI buses have been qualified as SCSI devices which meet NSE and LVD specifications. Contact your local HP sales representative for a current list of SCSI devices supported by HP for use on the Ultra Narrow Single-Ended and Ultra2 Wide Low-Voltage Differential SCSI buses.

If devices other than those supported by HP are connected to the Ultra Narrow Single-Ended or the Ultra2 Wide Low-Voltage Differential SCSI

86

Chapter 4