Detection of noise within an operating frequency on a network

• US 7,587,662 B2
• Filed: 09/29/2005
• Issued: 09/08/2009
• Est. Priority Date: 09/29/2005
• Status: Active Grant

• Current Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Original Assignee: Fisher-Rosemount Systems Incorporated (Emerson Electric Company)
• Inventors: Ferguson, Anthony D., Zielinski, Stephen A.
• Primary Examiner(s): Abraham; Esaw T
• Application Number:
  US11/238,655
• Publication Number:
  US 20070074085A1
• Time in Patent Office: 1,440 Days
• Field of Search: 714/25, 714/48, 714/700, 714/704, 714/776, 714/775, 714/807, 714/819
• US Class Current: 714/819
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 1/24 Testing correct operation
• CPC Class Codes: H04L 12/40 Bus networks
• CPC Class Codes: H04L 12/40032 Details regarding a bus interface enhancer
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling
• CPC Class Codes: H04L 2001/0094 Bus
• CPC Class Codes: H04L 2012/40221 Profibus
• CPC Class Codes: H04L 41/06 Management of faults, events, alarms or notifications
• CPC Class Codes: H04L 43/12 Network monitoring probes
• CPC Class Codes: H04L 43/16 Threshold monitoring

Abstract

Noise is detected within an operating frequency of a communication medium. Messages are monitored on the communication medium for corrupted messages. A noise detected signal is generated when a number of corrupted messages detected reaches a corrupted message threshold.

Claims

1. A method for detecting noise within an operating frequency of a communication medium, the method comprising:

monitoring messages on the communication medium;

detecting corrupt message count when a corrupt message is detected;

updating a corrupted message count when a corrupt message is detected;

detecting loss of communication with a device connected to the communication medium;

detecting a block of stale data;

comparing the corrupted message count with a corrupted message threshold (a) when loss of communication with a device is detected, or (b) when a block of stale data is detected;

generating a noise detected signal when the corrupted message count has reached the corrupted message threshold; and

generating an audible or visual output in response to the noise detected signal.

2. The method of claim 1, wherein the corrupted message threshold is related to a number of corrupted messages detected over a period of time.

3. The method of claim 1, wherein the corrupted message threshold is a ratio of the number of corrupted messages detected to all messages on the communication medium.

4. A diagnostic tool for connecting to a communication medium, the diagnostic tool comprising:

a medium attachment unit (MAU) connected to the communication medium to receive signals from the communication medium;

a communication controller connected to the MAU which is operable to detect corrupted messages on the communication medium and update a corrupted message count when a corrupted message is detected;

a processor connected to the communication controller which is operable to generate a noise detected signal when the corrupted message count has reached a corrupted message threshold, wherein the processor (a) requests a value of the corrupted message count when the processor detects a loss of communication with a device connected to the communication medium, or (b) requests a value of the corrupted message count when the processor detects a block of stale data.

5. The diagnostic tool of claim 4, wherein the corrupted message threshold is related to the number of corrupted messages over a period of time.

6. The diagnostic tool of claim 4, wherein the corrupted message threshold is a ratio of the number of corrupted message signals generated to all messages on the communication medium.

7. The diagnostic tool of claim 4, wherein the corrupted message threshold is provided in software executed by the processor.

8. The diagnostic tool of claim 4, wherein the corrupted message count is stored in a register in the communication controller.

9. A method for detecting noise within an operating frequency of a communication medium, the method comprising:

detecting a corrupted message on the communication medium;

updating a corrupted message count when a corrupted message is detected;

detecting loss of communication with a device connected to the communication medium;

detecting a block of stale data;

requesting the corrupted message count (a) when loss of communication with a device is detected, or (b) when a block of stale data is detected;

generating a noise detected signal if the corrupted message count has reached a corrupted message threshold; and

generating an audible or visual output in response to the noise detected signal.

10. The method of claim 9, wherein the corrupted message threshold is related to the number of corrupted messages detected over a period of time.

11. The method of claim 9, wherein the corrupted message threshold is a ratio of the number of corrupted message signals generated to all messages on the communication medium.

12. The method of claim 9, wherein detecting a corrupted message on the communication medium comprises performing a check of the frame check sequence (FCS) checksum on a message to determine whether it is corrupted.