HP b1000 88

NOTE

SCSI Connections

SCSI Bus Length Constraints

This section discusses SCSI bus length constraints for the Ultra Narrow Single-Ended SCSI bus and the Ultra2 Wide Low-Voltage Differential SCSI bus.

Ultra Narrow Single-Ended SCSI Bus Length

The maximum cable length for an Ultra Narrow Single-Ended SCSI bus is 3 meters. The HP VISUALIZE B1000/C3000 system uses a small portion of this maximum cable length.

When calculating the total Ultra Narrow Single-Ended SCSI cable/bus/trace length used externally, remember to account for cables connecting external devices together as well as the bus length internal to those devices.

There are two total cable length speciﬁcations that apply to the Ultra Narrow Single-Ended SCSI bus on your computer. Note that these speciﬁcations are based on the requirement that the SCSI device being connected to the NSE SCSI bus does not exceed the maximum capacitance of 25 picofarads (pF). Please check with the vendor of your SCSI device if you are not sure of your devices maximum capacitance.

Here are the total cable length speciﬁcations:

•For a total of one to four devices being connected to the NSE SCSI bus the total length of cable used should not exceed 3.0 meters.

•For a total of ﬁve to eight devices being connected to the NSE SCSI bus the total length of cable used should not exceed 1.5 meters.

Please remember that the computer is counted as one of the total devices, and the internal length of its cabling is 0.15 meters. This length needs to be considered in your total cable length determination.

Chapter 4