Connecting External Options
Table 3 shows the maximum cable lengths for connecting SCSI
devices, based on data-transmission rates.
Note: The maximum cable length for an external cable is
determined by subtracting the length of the internal cable
being used from the maximum length of SCSI cable that can
be used based on the speed of the data transfer.
Table 3. Maximum External SCSI Cable Lengths
5 MB Per Second or Slower Data Transmission Rates
Note: Maximum cable length
−
internal cable length = external cable length.
Maximum Length of SCSI cable = 6 meters (19.7 ft.)
Length of 4-drop, SCSI narrow cable = 1 meter (3.3 ft.)
Length of 7-drop, SCSI Fast/Wide cable = 1.5 meters (4.9 ft.)
When a narrow internal cable is used, the maximum length of the SCSI
external cable = 5 meters (16.4 ft.)
6 meters
−
1 meter = 5 meters, or
19.7 ft.
−
3.3 ft. = 16.4 ft.
When a Fast/Wide internal cable is used, the maximum length of the SCSI
external cable = 4.5 meters (14.8 ft.)
6 meters
−
1.5 meters = 4.5 meters, or
19.7 ft.
−
4.9 ft. = 14.8 ft.
Greater Than 5 MB Per Second Data Transmission Rate
Note: Maximum cable length
−
internal cable length = external cable length.
Maximum Length of SCSI cable = 3 meters (9.8 ft.)
Length of 4-drop, SCSI narrow cable = 1 meter (3.3 ft.)
Length of 7-drop, SCSI Fast/Wide cable = 1.5 meters (4.9 ft.)
When a narrow internal cable is used, the maximum length of the SCSI
external cable = 2 meters (6.5 ft.)
3 meters
−
1 meter = 2 meters, or
9.8 ft.
−
3.3 ft. = 6.5 ft.
When a Fast/Wide internal cable is used, the maximum length of the SCSI
external cable = 1.5 meters (4.9 ft.)
3 meters
−
1.5 meters = 1.5 meters, or
9.8 ft.
−
4.9 ft. = 4.9 ft.
Chapter 6. Installing Options
295
Summary of Contents for PC Server 520
Page 1: ...PC Server 520 User s Handbook for PCI Micro Channel IBM...
Page 86: ...Installation Checklist 70 PC Server 520 User s Handbook for PCI Micro Channel...
Page 146: ...Using the Mini Configuration Program 130 PC Server 520 User s Handbook for PCI Micro Channel...
Page 190: ...Using the SCSISelect Utility Program 174 PC Server 520 User s Handbook for PCI Micro Channel...
Page 385: ...Installing Additional Test Programs 207 CMD 3 Chapter 7 Solving Problems 369...
Page 438: ...IBM Part Number 78H6336 Printed in U S A May 1996 78H6336...