SCSI Termination. Mylex DAC960PG

SCSI Termination

SCSI Termination

The DAC960PG and DAC960PJ are equipped with automatic SCSI termination circuitry. If the controller is at the end of a SCSI bus, it automatically enables on-board termination.

If all the SCSI devices on a channel are connected either to an internal connector of a channel, or to an external connector of a channel, the end of the SCSI bus farthest from the controller must have a terminator installed. In this case, the controller automatically enables on-board termination. See

Figure 2-1 for examples of internal or external drive configurations.

If some SCSI devices are connected to the internal connector of a channel, and some are connected to the external connector of the same channel, the two ends of the SCSI bus farthest from the controller must each be terminated. In this case, the controller automatically disables on-board

termination. See Figure 2-1 for an example of an internal – external drive

configuration.

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Note

For this discussion, assume that the illustrated internal and external connectors are both on the same channel.

It is better to terminate the ends of the SCSI bus itself than it is to terminate the end devices on the bus. This allows hot swap devices to be added or removed from the SCSI bus without affecting termination.

2-2 DAC960PG/PJ Installation Guide

Preinstallation Planning

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Auto Termination Enabled

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External Drive Configuration

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Auto Termination Enabled

Internal Drive Configuration

Auto Termination Disabled

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Internal – External Drive Configuration

Figure 2-1. DAC960 Controller Termination Examples

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Manual Number 775012 2-3