Multi-rate optimized connection between industrial control scanner and industrial controller

• US 7,660,920 B2
• Filed: 09/27/2006
• Issued: 02/09/2010
• Est. Priority Date: 09/30/2005
• Status: Active Grant

• Current Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Original Assignee: Rockwell Automation Technologies Incorporated (Allen-Bradley Co., Inc.)
• Inventors: Cachat, Anthony J., Pierce, Scott A.
• Primary Examiner(s): Kindred; Alford W
• Assistant Examiner(s): Abad; Farley J
• Application Number:
  US11/528,202
• Publication Number:
  US 20070076267A1
• Time in Patent Office: 1,231 Days
• Field of Search: 710/61, 710/52, 710/36, 710/60, 714/4, 709/201
• US Class Current: 710/52
• CPC Class Codes: G05B 19/054 Input/output
• CPC Class Codes: G05B 2219/1166 Create optimum data blocks for transmission
• CPC Class Codes: G05B 2219/15023 Data packet, each module reads input stream and replaces with output
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways

Abstract

An industrial controller may communicate with a number of input/output (I/O) modules using an optimized connection packet assembled by a scanner communicating directly with the I/O modules and forwarding the optimized connection packet to the industrial processor. The optimized connection packet is communicated over a connection as part of a connected messaging system used to ensure highly reliable network communication. The need for higher data rates for some I/O modules as part of the optimized connection packet may be accommodated through the opening of a second redundant connection that provides the high-data-rate data in an interleaving fashion with the optimized connection packet, without upsetting the optimized connection packet or changing the use of the data by the industrial control program.

Claims

1. An industrial control system comprising:

a plurality of Input/Output (I/O) modules operable to interface with a process to exchange I/O data with the process;

a scanner operable to exchange the I/O data with the I/O modules and create an optimized connection packet including the I/O data for each I/O module arranged in an unformatted data block;

an industrial controller operable to exchange the optimized connection packet with the scanner in a first connected message at a first rate at first times, wherein the first connected message pre-allocates network bandwidth and buffer space, and to exchange a subset of the optimized connection packet with the scanner at a second rate in a second connected message at second times interleaved with the first times wherein the first connected message stores the I/O data contained within the optimized connection packet in a buffer and the second connected message stores the I/O data contained within the subset of the optimized connection packet in the same locations of the buffer as the I/O data from the first connected message; and

wherein the I/O data contained within the subset of the optimized connection packet is delivered more frequently than I/O data of the optimized connection packet other than the subset of the optimized connection packet.

2. The industrial control system of claim 1 wherein the subset of the optimized connection packet is defined by the I/O data of given I/O modules.

3. The industrial control system of claim 1 wherein the second rate is equal to the first rate whereby the I/O data of the subset of the optimized connection packet is delivered twice as fast as other I/O data of the optimized connection packet.

4. The industrial control system of claim 1 wherein the first times are equally spaced between the second times.

5. The industrial control system of claim 1 wherein the second rate is greater than the first rate whereby the subset of the optimized connection packet is delivered twice as fast as the I/O data of the optimized connection packet other than the subset of the optimized connection packet.

6. The industrial control system of claim 1 wherein the scanner builds the optimized connection packet in a scanner buffer and wherein the first and second connected messages use the scanner buffer for corresponding data.

7. The industrial control system of claim 1 wherein the scanner communicates with the plurality of I/O modules at a plurality of different times.

8. A method of operating an industrial control system comprising the steps of:

(a) connecting a plurality of I/O modules to a scanner, the I/O modules operable to interface with a process to exchange I/O data with the process;

(b) exchanging I/O data between the I/O modules and the scanner to create in the scanner an optimized connection packet including the I/O data for each I/O module arranged in an unformatted data block;

(c) opening a first connection between the scanner and an industrial controller to exchange the optimized connection packet with the industrial controller in a first connected message at a first rate at first times, wherein the first connected message pre-allocates network bandwidth and buffer space;

(d) storing the I/O data contained within the optimized connection packet in a buffer;

(e) opening a second connection between the scanner and the industrial controller to exchange a subset of the optimized connection packet with the industrial controller in a second connected message at a second rate at second times interleaved with the first times; and

(f) storing the I/O data contained within the subset of the optimized connection packet in the same locations of the buffer as the I/O data from the first connected message,

wherein the I/O data contained within the subset of the optimized connection packet is delivered more frequently than I/O data of the optimized connection packet other than the subset of the optimized connection packet.

9. The method of claim 8 wherein the second connection is opened at a time after a period of operation of the industrial controller.

10. The method of claim 8 wherein the subset of the optimized connection packet is defined by the I/O data of given I/O modules.

11. The method of claim 8 wherein the second rate is equal to the first rate whereby the I/O data of the subset of the optimized connection packet is delivered twice as fast as other I/O data of the optimized connection packet.

12. The method of claim 8 wherein the first times are equally spaced between the second times.

13. The method of claim 8 wherein the second rate is greater than the first rate whereby the subset of the optimized connection packet is delivered twice as fast as other I/O data of the optimized connection packet.

14. The method of claim 8 wherein the scanner builds the optimized connection packet in a scanner buffer and wherein first and second connections use the scanner buffer for corresponding data.

15. The method of claim 8 wherein the scanner communicates with the plurality of I/O modules at a plurality of different times.

16. A computer program stored in a computer memory for operating an industrial control system having a plurality of I/O modules connected to a scanner, the I/O modules operable to interface with a process to exchange I/O data with the process;

the scanner operable to collect I/O data exchanged between the I/O modules and the scanner into an optimized connection packet including the I/O data for each I/O module arranged in an unformatted data block, the computer program executing to;

(i) open a first connection between the scanner and an industrial controller to exchange the optimized connection packet with the industrial controller in a first connected message at a first rate at first times, wherein the first connected message pre-allocates network bandwidth and buffer space;

(ii) store the I/O data contained within the optimized connection packet in a buffer;

(iii) open a second connection between the scanner and the industrial controller to exchange a subset of the optimized connection packet with the industrial controller in a second connected message at a second rate at second times interleaved with the first times; and

(iv) store the I/O data contained within the subset of the optimized connection packet in the same locations of the buffer as the I/O data from the first connected message,

wherein the I/O data contained within the subset of the optimized connection packet is delivered more frequently than I/O data of the optimized connection packet other than the subset of the optimized connection packet.