Reproduce the smallest CAN-visible contract that answers the receiver test: the correct DBC revision, frame identifiers, signal encoding, known start values, coordinated transitions, expected rates, and defined invalid or recovery states. Preserve the scenario and its evidence so another operator can run the same input again.
Start with the receiver, not a list of every vehicle signal
Trying to model an entire vehicle creates work without improving a focused bench decision. Begin with the downstream feature and trace backward to the messages it actually consumes.
- Name the receiver state, calculation, display, log record, or fault response under test.
- List only the messages and signals needed to reach and observe that result.
- Confirm the approved DBC revision, units, scaling, signedness, bounds, and frame format.
- Write the start state, timed transitions, valid combinations, and expected receiver evidence.
- Identify what must be observed in simCAN, at the adapter, on the wire, and in the receiver.
The CAN test case template keeps this contract with the scenario and run record.
Build a small state path before adding edge cases
| Scenario phase | Profile decision | Receiver evidence |
|---|---|---|
| Known idle | Set every enabled signal to an explicit initial value and hold long enough for initialization. | The receiver reaches the documented ready or idle state. |
| Enter operating state | Change the minimum coordinated inputs in the intended order. | The expected mode, calculation, display, or log field becomes active. |
| Primary variation | Use a ramp, step, or hold that crosses the threshold relevant to the test. | The receiver response matches the prewritten result for each phase. |
| Invalid or missing update | Include only when the DBC and test plan define the representation and safe bench behavior. | The receiver follows the documented fallback or diagnostic path. |
| Recovery | Return signals to a valid state and define the expected ordering. | The receiver exits the fault or temporary mode as planned. |
| Repeat boundary | Check the last-to-first transition before looping the scenario. | No unintended jump or state change is introduced by repetition. |
Use the free 12-second sample as a visible starting point
The simCAN starter pack contains a generic VehicleSpeed profile and matching example DBC. It holds zero, ramps upward, holds, falls, and returns to zero over 12 seconds. The sample is designed to make the DBC-to-Excel-to-profile workflow easy to inspect; it is not a claim about a particular vehicle, network, or controller.
- Import the sample and confirm the plotted phases in Dry run.
- Replace the example definition with the approved DBC for the test.
- Reduce the enabled set to the receiver contract.
- Add coordinated signals and expected results one state at a time.
- Save the DBC, workbook, bus settings, and test record together.
Use the signal-profile authoring guide for ramps, holds, steps, recovery phases, and shared timelines.
Separate a credible scenario from proof of delivery
| Observation | It supports | It does not independently prove |
|---|---|---|
| Profile plot and Dry run | The intended values and internal sequence are present. | Adapter operation, wire traffic, or receiver delivery. |
| Validation result | The loaded definitions passed the checks reported by the application. | That the DBC matches an external system. |
| Schedule health and accepted sends | The application and adapter path accepted the tested workload as reported. | Independent wire-level timing or downstream processing. |
| External bus observation | Traffic was observed on the tested CAN path. | That the receiver interpreted every value correctly. |
| Receiver log or behavior | The downstream system produced the recorded result for this setup. | Performance outside the saved conditions. |
When rates or delivery are part of pass/fail, use the CAN timing and evidence guide and an independent analyzer or receiver-side record.
Know when generated vehicle behavior is the wrong starting point
Use record and replay when a real capture already contains the baseline traffic you need to reproduce. Use a generated scenario when the source system is unavailable, a deliberate threshold crossing is required, or the edge case has not occurred in a capture. A strong regression plan can replay the baseline, generate one controlled variation, and compare the downstream result.
Read the record/replay comparison before deciding. For a broader fit decision, use the CAN simulator selection guide.
Build one receiver path before expanding the vehicle model.
Inspect the free DBC and Excel sample, define the smallest useful vehicle-state sequence, then qualify the scenario on the Windows machine, adapter, bus, and receiver that matter.