Method and apparatus for monitoring a communications network

• US 5,442,639 A
• Filed: 10/12/1993
• Issued: 08/15/1995
• Est. Priority Date: 10/12/1993
• Status: Expired due to Fees

• Current Assignee: Ship Star Associates, Inc.
• Original Assignee: Ship Star Associates, Inc.
• Inventors: Crowder, Robert S., Binder, George E.
• Primary Examiner(s): Nguyen, Hoa T.
• Assistant Examiner(s): Palys, Joseph E.
• Application Number:
  US08/135,330
• Time in Patent Office: 672 Days
• Field of Search: 395/575, 371/32, 371/20.1, 371/11.2, 371/29.5
• US Class Current: 714/712
• CPC Class Codes: H04L 43/0847 Transmission error
• CPC Class Codes: H04L 43/12 Network monitoring probes

Abstract

A method and apparatus for the monitoring, detecting and analyzing of signal errors on an electronic communications network, utilizing a communication signal on a fieldbus of the network, which includes receiving a communication signal from the communications network, and collecting information electronically on the components of each individual signal frame. This information is selected electronically by use of a software driven microcomputer. The communication signal is sent through an active real time filter array which actively passes selected individual frames. The filters are selected electronically by use of a software driven microcomputer. The filters may use context information present on the fieldbus in selecting frames. A software driven microcomputer is also used to display these individual frames in real time. Additionally, frames may be captured manually or automatically and stored electronically. Automatic capturing is accomplished by use of a trigger mechanism set by the microcomputer. A simulator may also be included for generating a simulated communication signal to be displayed simultaneously with the communication signal.

Claims

1. A method for monitoring, detecting and analyzing signals and errors on a fieldbus communication network, utilizing a communication signal on a fieldbus within said fieldbus communication network, comprising the steps of:

receiving said communication signal from said fieldbus communication network;

identifying characteristic fieldbus protocol information on one or more signal frames from said received communication signal being used on said fieldbus communication network;

actively filtering said received communication signal in real time based on said identified characteristic fieldbus protocol information to separate frames indicative of errors in said fieldbus communication network or of operation or function of one or more fieldbus devices on said fieldbus communication network from among said signal frames.

2. The method of claim 1, further comprising the steps of triggering the capture of said frames, capturing said frames in a capture buffer, and storing said captured frames electronically.

3. The method of claim 2, wherein said flames are captured continuously in said capture buffer, contents of said capture buffer being frozen after a preselected number of flames have been captured.

4. The 5method of claim 1, wherein said active filtering step uses said characteristic fieldbus protocol information, concerning addresses or identifiers, contained in said frames to select said frames or deselect other related frames not concerning said addresses or identifiers.

5. The method of claim 1, further comprising the step of generating a simulated communication signal, and displaying said simulated communication signal simultaneously with said communication signal for causing and/or detecting signal errors or sequences of communication.

6. The method of claim 1, further comprising the step of filtering transactions of said selected frames separately.

7. The method of claim 1, further comprising the step of collecting statistics in real time on one or more of said signal frames, based upon said characteristic information.

8. The method of claim 1, wherein said selected individual frames are displayed in a parsed real time display.

9. The method of claim 1, further comprising the steps of triggering the capture of said frames, capturing said frames in a capture buffer, and displaying said captured frames.

10. The method of claim 1, further comprising the steps of triggering the capture of said frames, capturing said frames in a capture buffer, storing said captured frames electronically, and displaying said captured frames.

11. The method of claim 1, further comprising the step of displaying said separated frames in real time.

12. Apparatus for monitoring, detecting and analyzing signal errors on a fieldbus communication network, utilizing communication signals on a fieldbus within said fieldbus communication network comprising:

a probe including (i) an electronic signal detector for detecting said communication signals which are generated by one or more devices of said fieldbus communication network, (ii) an information collector for collecting characteristic fieldbus protocol information connected to said electronic signal detector, (iii) an active real time filter array connected to said information collector for separating selected frames of said communication signal based on said characteristic fieldbus protocol information, and (iv) a timer for synchronizing said probe with said frames; and

a user interface connected to said probe and including a communication signals detection controller, a controller for collection of said information, a controller for selection of said frames by said active real time filter array and a display for viewing said frames.

13. The apparatus of claim 12, further comprising a triggered capturing means for capturing said selected frames, based on the characteristics of said frames, and storing said frames, wherein said capturing means is controlled by said user interface and said probe.

14. The apparatus of claim 12, wherein said triggered capturing means is contained within said probe.

15. The apparatus of claim 13, wherein said frames are captured continuously in a capture buffer after capture begins and said trigger and capturing means freezes the captured frames of said buffer after a further selected number of frames have been collected.

16. The apparatus of claim 12, further comprising a simulator for generating a simulated communication signal, said simulated communication signal being displayed simultaneously with said communication signal for the detection of signal errors and operation of at least a portion of the network.

17. The apparatus of claim 12, wherein said selected individual frames are passed separately through said filter array based on each signal.

18. The apparatus of claim 12, wherein said user interface displays said frames in a parsed real time display.

19. A method for monitoring, detecting and analyzing signal errors on an electronic Fieldbus communications network, utilizing a communication signal on a fieldbus within said fieldbus communication network, comprising the steps of:

receiving said communication signal from said fieldbus communication network;

identifying characteristic fieldbus protocol information on one or more signal frames from said received communication signal being used on said fieldbus communication network;

actively filtering said received communication signal in real time, wherein said active filtering step uses said identified characteristic fieldbus protocol information, based upon addresses or identifiers contained or inferred in said signal frames, to select said signal frames or deselect other signal frames not containing or inferring said addresses or identifiers; and

displaying said signal frames.

20. The method of claim 19, further comprising the steps of:

triggering the capture of said frames, capturing said frames in a capture buffer, and storing said captured frames electronically;

wherein said frames are captured continuously in said capture buffer, the contents of said capture buffer being frozen after a preselected number of frames have been captured, wherein said characteristic information is selected from the group consisting of total received frames, frames without end delimiter, frames overrun to fieldbus interface, malformed frames, frames with bad FCS or CRC, and wherein said selected frames are displayed in a parsed real time display; and

generating a simulated communication signal, and displaying said simulated signal simultaneously with said communication signal for causing and/or detecting signal errors or sequences of communication.