Best of Techopedia weekly. News and Special Offers occasional. SCSI Termination. Types of termination: Single-ended SE — The SCSI controller pushes out signals to all devices using a single data line and each device at the end acts as a ground.
This is the most common signaling used in PCs. High-voltage differential HVD — Each device connected to the SCSI bus has a signal transceiver and uses this as a signal booster so that signals can reach further 25 m. This is usually used on servers. Low-voltage differential LVD — A variation of HVD, but instead of the transceiver being built into the device, it is smaller and built into the SCSI adapter on each device so the voltage required for communication is also lower.
Cheaper to implement compared to HVD but only has half the range at about 12 m. Related Question How can I set up cloud storage? Share this Term. Tech moves fast! Any devices attached beyond the terminator may not communicate with the controller. Single-ended: Single-ended terminators are referred to as passive or active. For Fast or Ultra single-ended buses, active termination is recommended for stable operation.
Many devices and terminators are "multimode ", capable of operating in either LVD or single-ended mode. The type of terminator you use depends on the interface type of your SCSI bus: Single-ended: Single-ended terminators are referred to as passive or active.
Translate to:. Send Feedback Questions, comments, suggestions? With some SCSI devices you must manually insert or remove the terminators. Other devices have built-in terminators that are enabled or disabled via switches or software commands.
Your host adapter and the SCSI devices attached to it must be properly terminated, or they will not work reliably. The SCSI bus must be properly terminated at both ends so that commands and datacan be transmitted to and from all devices on the bus.
This is roughly similar to sending vibrations back and forth over the length of a string that is firmly secured at both ends. If you hold the middle of the string, the vibrations cannot be transmitted.
This is similar to what happens to data and commands on the SCSI bus if you terminate a device in the middle of the bus. This information applies if your computer has a host adapter board. If you use SCSI in a laptop or notebook computer or if a host adapter chip is installed on your computer's motherboard, your host adapter device is automatically terminated, and you do not need to change its termination status.
Since there is no room to fit internal SCSI devices inside a laptop or notebook computer, you can only connect external SCSI devices to the host adapter device.
0コメント