Copyright ⌐ 1996, 1997 Tech Data Corporation

Configuration and Jumper Options

BEFORE YOU BEGIN

Record the drive model number and serial number. Both are located on the top of the drive.

Gather these supplies:
╖ Computer system manual
╖ Operating system manual
╖ Host bus adapter manual
╖ Non-magnetic screwdriver

You may also need:
╖ Jumper shunts, if you change the drive configuration
╖ Interface cable (for 5O-pin or 68-pin models).
╖ A drive tray or mounting rails, depending upon system requirements
╖ Additional power cable(s)

Table of Contents

HANDLING PRECAUTIONS
SETTING THE DRIVE JUMPERS
SCSI ID Numbers
Disable Auto Start
Auto Start Delay
SCAM
Disable Unit Attention
Disable Target Initiated Synchronous/Wide Negotiaton
SCSI Termination
Termination Power (TERMPWR)
LED Support
Reserved Pins
Mode Select Options
Remote Option Block
Multiple Drive Installations
INSTALLING THE DRIVE
Open the Computer
Prepare the Drive for Installation
If Your Drive has a 50-pin or 68-pin Connector
SCSI CABLE LENGTH RESTRICTIONS

HANDLING PRECAUTIONS

The WD Enterprise hard drive is designed to withstand normal handling during unpacking and installation. Care must be taken to avoid excessive mechanical shock or electrostatic discharge (ESD) that can permanently damage the drive and void the warranty. Be aware of the following precautions when unpacking and installing the WD Enterprise drive:
╖ Do not unpack the hard drive until you are ready to install it.
╖ Handle the drive by the sides only and avoid touching the circuit board components and connectors.
╖ Do not attempt to remove the drive cover. Servicing components in the sealed compartment require special cleanroom facilities. Failure to observe this restriction will void the warranty.
╖ For additional handling information, refer to the Western Digital 3.5- Inch Drive Handling Guide (document number S0999).

SETTING THE DRIVE JUMPERS

NOTE: This information will help you configure each WD Enterprise drive to operate properly in your system.

The drive is designed for use in a variety of systems. Therefore, you can set several configuration options using the option block on the front of the drive (end opposite SCSI connector). In most cases, you do not need to change the default settings for normal drive operation. However, some installations may require you to install or remove certain jumpers in order to meet system specifications. See Figure 1.

SCSI ID Numbers

Each device on the SCSI bus requires a unique SCSI ID number (0 to 7 for 8-bit devices, 0 to 15 for 16-bit devices).
Option block pins 1 through 8 are used to set the SCSI IDs. Refer to Table 1 for a complete matrix of jumper settings.
The host computer's SCSI controller typically uses ID number 7, and the other numbers are used for devices such as hard drives. The WD Enterprise drive has a default SCSI ID of 0.

Table 1 SCSI ID Jumpers

NOTE: IN = Jumper installed OUT = NO Jumper

Disable Auto Start

You can configure the WD Enterprise dnve to Auto Start, or automatically spin up when power is applied to the drive. If the drive is configured to disable Auto Start, it powers up, but does not spin up until a start unit command is issued by an operator.

Option block pins 13 and 14 are dedicated to the Auto Start option. To disable Auto Start, install a jumper as shown in Figure 2. To enable Auto Start, no jumper is required.

Auto Start Delay

This feature delays the start-up process to avoid an initial power surge when several drives power up at once. The delay time (default) is 4 seconds between drives, or the SCSI ID multiplied by 4 seconds. Let's say you have three hard drives in your system, and they are set to SCSI IDs 0, 1, and 2. The drive assigned as ID 0 powers up immediately; the drive assigned to ID 1 powers up in 4 seconds; and the drive assigned to ID 2 powers up in 8 seconds.

NOTE: You can change the 4-second delay time in the drives' mode parameter settings.

Option block pins 15 and 16 are dedicated to the Auto Start Delay option. (This option is valid only if the Disable Auto Start jumper is not installed.) To enable Auto Start Delay, install a jumper as shown in Figure 3. To disable Auto Start Delay no jumper is required.

SCAM

The WD Enterprise drive supports the SCSI Configured Automagically (SCAM) option, which allows it to function as a SCAM level 2 device.

NOTE: In order to use this feature, the host bus adapter must support SCAM

Option block pins 17 and 18 are dedicated to the SCAM feature. To enable SCAM, install a jumper as shown in Figure 4. To disable SCAM, no jumper is required.

Disable Unit Attention

Whenever a target (WD Enterprise drive) is reset by a power-on or reset sequence, it communicates a unit attention message to the initiator (host bus adapter).

Option block pins 19 and 20 are dedicated to the Disable Unit Attention option. To disable unit attention install a jumper as shown in Figure 5. To enable unit attention no jumper is required.

Disable Target Initiated Synchronous/Wide Negotiaton

During the power-up sequence, the initiator (host bus adapter) and the target (WD Enterprise drive) negotiate and agree upon three items: bus width, bus speed, and synchronous/asynchronous data transfer. Either the initiator or the target can start the negotiation process, and once this process is completed successfully, all "data in" and "data out" phases operate as determined during the handshake. The negotiation process occurs only once, usually during start-up.

Option block pins 21 and 22 are dedicated to the Disable Target Initiated Synchronous/Wide Negotiation option. To disable target initiated synchronous/wide negotiation, install a jumper as shown in Figure 6. To enable target initiated synchronous/wide negotiation, no jumper is required.

SCSI Termination

To ensure reliable communication, the SCSI bus must be properly terminated. Devices located at the physical ends of the SCSI bus should have their terminators enabled. All other devices must have their terminators disabled.

Option block pins 23 and 24 are dedicated to the SCSI Termination option. To enable SCSI termination, install a jumper as shown in Figure 7 To disable SCSI termination, no jumper is required.

Termination Power (TERMPWR)

WD Enterprise drives have the ability to supply +5V to the SCSI bus for termination. Option block pins 27 and 28 are dedicated to TERMPWR. If you want the drive to supply TERMPWR to the SCSI bus, install a jumper as shown in Figure 8. To disable TERMPWR, no jumper is required.

Consult your system or host bus adapter documentation to determine if the SCSI bus supplies termination power. (Most systems do supply termination power). If your system does not, then you must use the power supplied by the WD Enterprise drive.

NOTE: Termination power from the hard drive is required only if the host bus adapter does not supply it. However; both devices can provide termination power with no detrimental effects to the system.

LED Support

If your system configuration allows the use of an activity LED external to the WD Enterprise drive, you can power the LED from the drive. Pins 10 and 29 are dedicated to LED support, as shown in Figure 9. To install an external activity LED, connect the positive lead (anode) of the LED to pin 29 and the negative lead (cathode) to pin 10.

NOTE: These pins can be used to power an LED located on the front of the drive, Or an external LED in systems where the front of the drive cannot be seen.

Reserved Pins

Several pins on the option block are reserved for development and manufacturing purposes:

╖ Pins 25 and 26
╖ Pin 30
╖ Pins 31 and 32
╖ Pins 33 and 34
╖ Key slot (prevents incorrect installation of connector)

Mode Select Options

You can alter certain configuration parameters using the SCSI Mode Select command. Some examples include Read/Write Error Recovery Page, Format Device Page, and Caching Page. The Mode Select command allows drive characteristics to be customized to meet your system require ments. Refer to the Western Digital SCSI Implementation Guide (document number 4096-001116) for more information.

Remote Option Block

WD Enterprise 68-pin drives are equipped with a remote option block that allows you to set SCSI IDs and enable select options such as termination and LED power. Customers using the remote option block typically use a pre-fabricated cable for convenient connection to the host. Do not use jumpers on this option block. For more information, refer to the WD Enterprise Technical Reference Manual (document number 4079-001045).

Multiple Drive Installations

If your system requires multiple devices, you may install up to eight SCSI devices (including the host bus adapter) on an 8-bit SCSI bus; up to 16 SCSI devices (including the host bus adapter) on a 16-bit SCSI bus, or up to 32 devices (including the host bus adapter) on a 16-bit SCSI bus with, dual processor host bus adapter. Refer to the SCSI ID Numbers section.

INSTALLING THE DRIVE

Because the Enterprise WDE2l70 and WDE4360 drives are compatible with a wide range of computer systems and host bus adapters, this manual does not include system-specific information. If the information contained in the following sections does not apply to your setup, refer to your computer system documentation for further details.

Figure 10. Drive Drawing

Open the Computer

1. Turn OFF the power to the computer system and all attached peripheral devices.
2. Unplug the AC power cable from the wall outlet.
3. Remove all cables from the back of the computer system.
4. Remove the screws attaching the computer system's cover using a non-magnetic screwdriver. Be sure to keep all screws and other parts together for easy re-assembly.
5. Cently lift the cover and remove it from the chassis.
   

Prepare the Drive for Installation

NOTE. Refer to the Wettein Diotai 3. 5-Jnch Drive Handling Guide (document number 50999).

1. Remove the WD Enterprise drive from the anti-static bag, and place the drive on top of the anti-static bag on your work surface.
2. Configure the drive jumpers as necessary. Refer to "Setting the Drive Jumpers" for more details.
3. If SCSI termination must be provided by the WD Enterprise drive, ensure that the terminator is properly installed. Refer to SCSI Termination.

If Your Drive has a 50-pin or 68-pin Connector

1. Using a non-magnetic screwdriver and four mounting screws, mount the 50-pin or 68-pin drive in the computer sustem's mounting frame. Use four 6-32 mounting screws. Do not install the screws past .15-inch.

NOTE: When mounting the drive, make sure the SCSI connector and power connector face the rear of the chassis.

NOTE: If you plan to install the WD Enterprise drive in a 5.25-inch bay, you must install the mounting hardware. Contact your local dealer to obtain a mounting adapter kit. Rails are sometimes necessary to complete the installation. Consult your computer system manufacturer.

SCSI CABLE LENGTH RESTRICTIONS

Single-ended SCSI drives allow cable lengths of up to 6 meters (19.68 feet). Users who plan to use "Fast" and "Ultra Fast" data transfers with single-ended models should follow all the ANSI SCSI guidelines for these operations. Differential SCSI drives allow cable lengths of up to 25 meters (82.02 feet). Cables must meet the requirements for differential cables as set forth in the ANSI SCSI standard.

Drives equipped with a SCA-2 connector are not designed for direct cable attachment due to the combination of power and SCSI bus signals. The ANSI SCSI standard states that any stub from the main cable must not exceed 0.1 meters (.32 feet) for single-ended cables and 0.2 meters (.65 feet) for differential cables.

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