H50M SCSI II Active Terminator

Introduction

An active terminator in the context of SCSI (Small Computer System Interface) refers to a device that is used to terminate the ends of a SCSI bus to prevent signal reflections and improve data integrity. In the case of SCSI-2, HD50M (High-Density 50-pin Male) connectors were commonly used for connecting SCSI devices. The active terminator is an electronic component that actively manages the termination process by absorbing and dissipating signal reflections that can occur when a signal reaches the end of a transmission line. These reflections can cause data corruption and signal degradation.

Termination: SCSI devices are connected in a daisy-chain fashion along a SCSI bus. At both ends of the bus, proper termination is necessary to prevent signal reflections. Termination ensures that the signal is absorbed and doesn't bounce back, which can interfere with the communication.

Active Terminator: An active terminator includes electronic components that can actively adjust the impedance of the termination resistors. It can detect the incoming signals and adjust its impedance to match the impedance of the SCSI bus, effectively absorbing the signal energy and preventing reflections.

Signal Integrity: By actively managing the termination, an active terminator improves signal integrity and helps maintain the quality of data transmission across the SCSI bus. This is especially important in high-speed or long-distance SCSI setups where signal reflections can have a more pronounced impact.