Methods of and apparatus for monitoring the termination status of a SCSI bus
US6154067A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 5, 1998 |
| Grant date | Nov 28, 2000 |
| Priority date | — |
| Expiry date | Aug 5, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K5/19
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
When more than two terminators are on a SCSI bus the bus is said to be "over-terminated", and when less than two terminators are on the bus, the bus is said to be "under-terminated". When the SCSI bus is either under or over terminated, the bus does not function, and often the user does not know why the bus is not functioning. Apparatus and a method are provided for indicating to the user when the bus is not properly terminated. A terminator monitoring system and method operate in conjunction with the bus. A precision resistor is connectable to the bus so that a voltage drop is produced across the precision resistor. A circuit monitors the value of the produced voltage drop across the precision resistor to provide an indication of the number of terminators on the bus. A switch selectably connects the precision resistor to the bus, and there is a source of a reference voltage. The monitoring circuit includes a comparison circuit responsive to the voltage drop across the precision resistor and to the reference voltage for indicating whether the number of terminators on the bus exceeds a limit or is less than the limit. The system notifies a system user of an undesired (or improper) t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.