Elevator communications bus analyzer
US5294921A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1991 |
| Grant date | Mar 15, 1994 |
| Priority date | — |
| Expiry date | Nov 12, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L43/00
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method for allowing access to data frames on an elevator communications bus includes (a) disconnecting a remote station 117 from the communication bus 24; (b) connecting the elevator communications bus 24 to the elevator communications bus analyzer 100; (c) providing the power, return, clock, and data signals on lines 46a, 46b, 48a, 48b from the elevator communications bus analyzer 100 to the remote station 117 previously disconnected; (d) connecting receive or transmit trigger lines 120, 122 from the elevator communications bus analyzer 100 to an oscilloscope 24; (e) selecting an address of a remote station; (f) connecting clock and data signals on lines 46a, 46b to the oscilloscope 124; and (g) switching the oscilloscope 124 to its differential mode to provide on an oscilloscope screen the difference between the clock and data signals (the signal on line 46b minus the signal on line 46a) for the address so that an elevator mechanic may see the data bits on the elevator communications bus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.