Addressing for a multipoint communication system for patient monitoring
US4638313A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 8, 1984 |
| Grant date | Jan 20, 1987 |
| Priority date | — |
| Expiry date | Nov 8, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L61/5046
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method for dynamically assigning addresses to new modules as they are coupled to a communication system with a synchronous data link control (SDLC) bus is described. These modules communicate with a display unit via the SDLC bus. The SDLC bus is controlled by a primary station in the display unit, with all modules acting as secondary stations. The primary station periodically broadcasts a time-tag to all modules at a thirty-two hertz rate. At power up, each module obtains a number, module 16, derived from the lower four bits of its unique twenty-four bit serial number. The module uses this number as a count of the number of time-tags which must occur before the module responds to the primary with an address request. If there are no collisions with other modules, the primary sends the module a packet which assigns the module the next available address. In the event of a collision (i.e., two or more modules request an address at the same time), the primary SDLC controller detects a CRC error and ignores the SDLC frame. The modules will each time-out and obtain a new number, modulo 16, derived from the next significant four bits of the module serial number. This process continues un…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.