HP StorageWorks U320e SCSI Host Bus Adapter user guide (AH627-96001, March 2007)

The last device in the bus — that farthest from the adapter — must be properly terminated for each

SCSI bus. When planning device termination, keep the following in mind:

• Use an LVD terminator if you are only using LVD devices.

Although you can use a Single-Ended terminator, all devices will be limited to Ultra SCSI speeds and

cable lengths. S ingle-Ended devices require a Single-Ended terminator. If you use an LVD terminator

with Single-Ended devices, the system may ha ng or devices may not be seen on the SCSI bus. Some

termination manufacturers provide automatically sensing terminators.

• LVD Ultra2 and Ultra160 SCSI devices cannot supply their own termination.

• Wide (16-bit) and narrow (8-bit) devices can be c onnected together on the same connector of the

host adapter card, but wide devices must be attached ﬁ rst, followed by narro w dev ices.

To terminate the SCSI bus, the cable or adapter used to convert from a wide (68-pin) connector to

a n arrow (50-pin) connector provides partial termination, allowing the upper 8-bits (or byte) of the

wide SCSI bus to be properly terminated. A narrow terminator should be used on the last narrow

device to terminate the rest of the SCSI bus. A SCSI bus without par tial termination between the

wide and narrow devices may at ﬁrst appear to work correctly, but occasional I/O errors occur

without proper termination.

• Termination power: Host adapters supply termination power to the bus at all times and many

SCSI devices are also able to supply termination power. SCSI signal quality, particularly with long

or marginal quality cables, may be improved if the device supplies the termination power. See

your device documentation for information on your device's ability to supply termination power.

3. Review system documentation to select an appropriate slot to install the ad apter.

The combined power consumption of the expansion slots must not exceed the limits for your system.

If you have more than one expansion ca rd installed, ensure power consumption is within the limits

outlined for your system.

4. If the selected installation s lot is low proﬁle, replace the mounting bracket on the adapter.

a. Remove the two screws on top of the board that secure the bracket to the board, as shown in

Figure 2.

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Figure 2 Removing the bracket screws

User guide