Time triggered ethernet system testing means and method

• US 8,634,305 B2
• Filed: 09/02/2011
• Issued: 01/21/2014
• Est. Priority Date: 09/02/2011
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Smithgall, William Todd, Hall, Brendan, Varadarajan, Srivatsan
• Primary Examiner(s): HOANG, THAI D
• Application Number:
  US13/224,871
• Publication Number:
  US 20130058217A1
• Time in Patent Office: 872 Days
• Field of Search: 370241-251, 370503-519
• US Class Current: 370/241
• CPC Class Codes: H04L 43/50 Testing arrangements

Abstract

Methods and apparatus are provided for evaluating the performance of a Time Triggered Ethernet (TTE) system employing Time Triggered (TT) communication. A real TTE system under test (SUT) having real input elements communicating using TT messages with output elements via one or more first TTE switches during a first time interval schedule established for the SUT. A simulation system is also provided having input simulators that communicate using TT messages via one or more second TTE switches with the same output elements during a second time interval schedule established for the simulation system. The first and second time interval schedules are off-set slightly so that messages from the input simulators, when present, arrive at the output elements prior to messages from the analogous real inputs, thereby having priority over messages from the real inputs and causing the system to operate based on the simulated inputs when present.

Claims

1. A method is provided for in-place testing of Time Triggered Ethernet (TTE) command and control (C&

C) system having real input devices and output interfaces that communicate through one or more switches during first predetermined time intervals set by a time scheduling system associated with the C&

C system as to when outputs from the real input devices can be sent to the output interfaces, comprising;

providing a simulation subsystem having therein simulated input devices adapted to provide predetermined or dynamically calculated outputs mimicking the outputs of the real input devices and communicating with the output interfaces through at least a further switch during second predetermined time intervals set by a time scheduling system associated with the simulation subsystem system as to when outputs from the simulated input devices can be sent to the output interfaces; and

adjusting the second predetermined time intervals relative to the first predetermined time intervals, so that the outputs from the simulated input devices arrive at the output interfaces prior to the outputs from the real input devices.

2. The method of claim 1, wherein the adjusting step comprises adjusting the second predetermined time intervals relative to the first predetermined time intervals, so that the inputs from the simulated inputs arrive at the one or more output interfaces prior to the inputs from the input devices by an amount Δ

t of at least about 15 microseconds.

3. The method of claim 1, wherein Δ

t is in the range of about 150 to 300 microseconds for systems using 100 Megabit Ethernet.

4. The method of claim 1, wherein Δ

t is in the range of about 1500 to 3000 microseconds for systems using 10 Megabit Ethernet.

5. The method of claim 1, wherein the one or more output interfaces comprise serially coupled network interface controllers and output elements, and wherein the network interface controllers determine for each serially coupled output element the relative time of arrival of outputs from the input devices and outputs from the simulated input devices, and transmit only the first to arrive to the serially coupled output elements.

6. The method of claim 5, wherein the serially coupled output elements comprise one or more computers or control elements and at least one effector, and wherein the one or more computers or control elements receive the first to arrive outputs from the input devices, transform them and send them to the at least one effector to change the state thereof.

7. The method of claim 1, wherein the one or more output interfaces comprises an actuator and at least one computer or control element, and the simulated output from the simulated input devices is received first by the at least one computer or control element, modified therein and then transmitted to the actuator to change the state of the actuator.

8. The method of claim 7, wherein the one or more output interfaces further comprise network interface controllers serially coupled to the actuator and the at least one computer or control element for determining which of the outputs from the input devices and the outputs from the simulated input devices is the first to arrive and then sending the first to arrive outputs to the at least one computer or control element.

9. A system having built-in test simulation capability, comprising:

a real sub-system portion of the system, comprising;

one or more real input sensors;

one or more output interfaces; and

one or more first switches coupling the real input sensors and the one or more output interfaces;

wherein the real input sensors, first switches and one or more output interfaces communicate under a Time Triggered Ethernet (TTE) control and communication (C&

C) protocol wherein messages from the real input sensors to the one or more output interfaces are Time Triggered (TT) communications messages occurring during a predetermined first time interval established by a time schedule operation of the real sub-system portion of the system; and

a simulation sub-system portion of the system, comprising;

one or more input simulators adapted to provide predetermined or dynamically calculated output values mimicking operation of the real input sensors over a desired range of output values; and

one or more second switches adapted to couple the output values from the one or more input simulators to the one or more output interfaces under a Time Triggered Ethernet (TTE) control and communication (C&

C) protocol;

wherein messages from the input simulators to the one or more output interfaces are Time Triggered (TT) communications occurring during a predetermined second time interval at least partly overlapping the first time interval and established by a time schedule controlling operation of the simulation sub-system portion of the system, wherein a beginning of the second time interval precedes a beginning of the first time interval by an amount Δ

t.

10. The system of claim 9, wherein the amount Δ

t is at least about 15 microseconds.

11. The system of claim 9, wherein Δ

t lies in the range of about 150 to 300 microseconds for systems using 100 Megabit Ethernet.

12. The system of claim 9, wherein Δ

t lies in the range of about 1500 to 3000 microseconds for systems using 10 Megabit Ethernet.

13. The system of claim 9, wherein the one or more output interfaces comprise serially coupled network interface controllers and output elements, and wherein the network interface controllers determine which of the output values from the input simulators or the real inputs is first to arrive and sending the first to arrive to the output elements.

14. The system of claim 13, wherein the serially coupled output elements comprise one or more computers or control elements and at least one effector, and wherein the one or more computers or control elements receive the first to arrive outputs, transform them and send them to the at least one effector to change the state thereof.

15. The system of claim 9, wherein the one or more output interfaces comprises an actuator and at least one computer or control element, and the output from the input simulators is received first by the at least one computer or control element, modified therein and then transmitted to the actuator to change the state of the actuator.

16. The system of claim 15, wherein the one or more output interfaces further comprise network interface controllers serially coupled to the actuator and the at least one computer or control element for determining which of the outputs from the input sensors and simulated outputs from the simulated input sensors is the first to arrive and then sending the first to arrive inputs to the at least one computer or control element.

17. An apparatus for evaluating the performance of a control and communication (C&

C) system, comprising;

a real physical Time Triggered Ethernet (TTE) control and communication (C&

C) system under test (SUT), comprising real input elements, adapted to communicate using time triggered (TT) communication protocols with real output elements via one or more first switches during a first time interval schedule established for the SUT;

a simulation system having input simulators that communicate using TT communication with the real output elements via one or more second switches during a second time interval schedule established for the simulation system;

wherein the first and second time interval schedules are off-set by amount Δ

t so that messages from the input simulators when present arrive at the output elements prior to messages from the real input elements, thereby having priority over messages from the real input elements and causing the system to operate based on the messages from the input simulators when present.

18. The apparatus of claim 17, wherein the amount Δ

t is at least about 15 microseconds.

19. The apparatus of claim 17, wherein, the output elements comprise one or more serially coupled network interface controllers and output processors or effectors.

20. The apparatus of claim 17, wherein, the output elements comprise one or more network interface controllers adapted to receive signals transmitted by the one or more first and second switches and send them to one or more output processors for manipulating the signals received from the first and second switches and transmitting such manipulated signals to an effector to change its state.