Control system network structure

• US 5,274,311 A
• Filed: 11/13/1991
• Issued: 12/28/1993
• Est. Priority Date: 11/13/1991
• Status: Expired due to Fees

• Current Assignee: Quest Data Technologies, Inc.
• Original Assignee: Quest Technologies, Inc. (3M Company)
• Inventors: Golini, John, Littlejohn, Douglas J.
• Primary Examiner(s): Ro, Bentsu
• Application Number:
  US07/792,217
• Time in Patent Office: 776 Days
• Field of Search: 364/424.01, 364/424.05, 364/426.01, 318/567, 318/568.1, 318/568.11, 318/568.16, 318/568.17, 318/568.18, 318/568.2, 318/568.24, 318/562, 318/139, 318/565, 318/569, 318/600, 370/77, 370/82, 370/83, 370/85.1, 370/105.1, 340/870.13, 340/870.14
• US Class Current: 318/562
• CPC Class Codes: G05B 19/4142 characterised by the use of a microprocessor G05B19/4141 takes precedence
• CPC Class Codes: G05B 2219/31094 Data exchange between modules, cells, devices, processors
• CPC Class Codes: G05B 2219/33126 Identification of address connected module, processor
• CPC Class Codes: G05B 2219/33144 Module clock, synchronised by controller message, to send message in time slice
• CPC Class Codes: G05B 2219/33214 Bus between different axis controllers and cpu
• CPC Class Codes: G05B 2219/33228 Detection of line failure, breakage of transmission, failure of receiver
• CPC Class Codes: G05B 2219/33229 Differential amplifier, xor to cancel noise, balanced rs422
• CPC Class Codes: G05B 2219/34208 Motion controller
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

The present invention imports network communication concepts into a motor and/or motion control system. The motor and/or motion control system is divided into various modules. A preferred configuration includes a motor drive control module, a user command module, and a master control module. The modules are interconnected by a simple hardware bus, such as an RS-485 bus. Communication between the modules is accomplished using a time division protocol.

Claims

1. An apparatus for communicating between modules of a motor control system, comprising:

a motor control module;

an input/output module;

a processing module;

means for storing a unique ID in each of said modules;

a bus interconnecting said modules;

means for transmitting information from each of said modules over said bus in a time frame corresponding to such module; and

means for monitoring said bus at each of said modules and updating an internal clock used to track said time frames in response to a detected transmission;

wherein said bus comprises a two wire differential data link and further including an emergency line in parallel with said data link for sending a shut-down signal in parallel with communications over said data link in the event of a failure of said data link or a receiver in one of said modules coupled to said data link.

2. An apparatus for communicating between modules of a motor control system, comprising:

a motor control module;

an input/output module;

a processing module;

means for storing a unique ID in each of said modules;

a bus interconnecting said modules;

means for transmitting information from each of said modules over said bus in a time frame corresponding to such module; and

means for monitoring said bus at each of said modules and updating an internal clock used to track said time frames in response to a detected transmission;

wherein a transmission in one of said time frames consists of an address byte, followed by multiple data bytes, followed by a pair of CRC error detection bytes.

3. The apparatus of claim 2 wherein said address byte includes source address bits followed by data type bits.