Applications / Interoperability & Charging Analysis
Charging interoperability: analyse EV and EVSE failures
Charging interoperability analysis connects the messages, voltage and current of a real electric vehicle and charging station on one timeline. Compare their reactions, locate the first mismatch and test the suspected cause. Repeat the session after the correction.
Plan the interoperability investigation
Start with the real charging pair.
Identify the EV and EVSE involved. Use the documented diagnosis case to follow the method, then choose the measurements your charging pair needs.
Test scenario: Start with the precharge mismatch
In the documented customer case, the voltage requested by the vehicle did not match the charging station’s measured precharge response. Precharge prepares the voltage before the main power connection closes. Compare the request, measured voltage and next state together, then repeat the charging attempt after the control parameters have been corrected.
Compare the timing with the measured voltage.
In an anonymised EVSE (electric vehicle supply equipment, or charging station) case, the requested battery voltage and measured precharge response did not match. Reviewing communication and electrical signals together made the mismatch visible.
Tracing charging interoperability failures
Bring vehicle and charging-station records onto one timeline.
Charging failure analysis follows the sequence across communication, low-level control and electrical behaviour. Separate PCAP files, vehicle logs and charger traces may show the final error while leaving the first deviation unclear.
Align the clocks
Vehicle, charging station, backend and laboratory tools often use different time bases. When records are aligned manually, the apparent order of events can change.
Compare all relevant signals
Check the decoded messages against low-level states, voltage, current and the expected charging phase. Messages alone cannot establish that these remained consistent.
Test the suspected cause
Use the same conditions to test the suspected cause before changing software. This gives both teams a basis for discussing symptoms that appeared in separate exports.
Passive Man-in-the-Middle measurement
Record the real vehicle and charging station together.
Passive Man-in-the-Middle measurement records the relevant layers at the physical charging interface on one time base. Both real partners stay connected, so the interaction that produced the problem is preserved.
Capture the original event and define the engineering question first. Then use active manipulation or laboratory simulation as separate validation steps.
Cross-layer charging analysis
Check the charging process across messages and measurements.
Charging interoperability analysis compares protocol messages, timing, low-level states, voltage, current and both partners’ reactions. Review them against the charging phase to find the first technically meaningful deviation.
Check that messages, states and measurements agree.
Message direction, sequence, content and timing.
Connection, control, signaling and stop conditions.
Voltage, current, power transition and physical reaction.
Charging phase, permitted combination and identified deviation.
Automated Standards Analysis can add normative or configured expectations where released. Cross-Layer State Monitoring is implemented for applicable DC CCS, CHAdeMO and DC China / GB/T DC configurations. Check the exact protocol versions, channels and evaluation rules for your selected product and capability.
One charging interoperability method
From the charging session to a repeatable test.
- 1Connect
Connect to the real EV and EVSE at the charging interface.
- 2Capture
Capture the relevant charging layers on one synchronised time base.
- 3Decode
Decode messages and identify state transitions, signals and timing.
- 4Correlate
Compare communication with low-level signals and electrical behaviour.
- 5Analyse
Find the first deviation from the expected charging state.
- 6Validate
Change one controlled condition to test the suspected cause.
- 7Reproduce
Reproduce supported partner behaviour in a repeatable laboratory test.
- 8Reuse
Keep the case for supplier discussions, regression tests and documentation.
Validate the cause and reproduce the field case
Check cause and effect before changing the product.
Once the first deviation is isolated, change one condition to test its effect. The live gateway keeps both real partners connected. Playback can later reproduce supported partner behaviour at the physical interface.
Test with both real partners connected
Use Manipulating Gateway where released to test whether a selected value, message or timing condition changes the result.
Manipulating GatewayRepeat the partner behaviour in the laboratory
Use Charge Playback where released to present recorded EV-side or EVSE-side behaviour to the device under test again.
Charge Playback
Keep the recording and test conditions together
Record the case, repeat the conditions and verify the correction.
Save the synchronised measurement with the expected behaviour, observed deviation, validation condition and decision. Keep the link to the original event so others can follow how the conclusion was reached.
- Communication and measurements on one synchronised time base
- Expected state, observed behaviour and deviation shown together
- Documented conditions for the controlled validation test
- Shared evidence for development, suppliers and laboratories
- A reusable case for release regression and variant testing
Use the same case in development, supplier discussions and field support.
Where to use charging interoperability analysis
Resolve integration failures before release
Investigate the interaction while changes to vehicle and charging-station software can still be planned and tested.
Record the charging pair at the site
Capture the event while both implementations are still at the site and their original interaction can be observed.
Give both teams the same recording
Vehicle and charging-station teams review the same time base, event sequence and tested hypothesis.
Repeat verified cases after updates
Repeat the relevant partner behaviour after software, parameter or hardware changes.
Choose the next test step.
From method to implementation
Choose the next task: record a real charging pair, reproduce partner behaviour, configure faults or select a complete test system.
Use EVCA Interop to record communication and measured signals from the real vehicle and charging-station pair.
Broader portable measurement, simulation and multi-standard field work.
See the released standards-aware evaluation and timing analysis functions, with examples from the user interface.
Supported live changes, protocol scope, limits and validation conditions.
CapabilityActive physical charging-partner reproduction, direction and release depth.
Defined test cases, standard editions, DUT roles, verdicts and validation scope.
Conformance, interoperability and robustness
Choose the test discipline for the question.
Conformance
Does one implementation meet a defined requirement set and standardized test cases?
Interoperability
How do two specific implementations work together during a real charging session?
Robustness
How does an implementation respond to configured limits, timing changes and difficult partner behaviour?
Customer references
Customer experience with real charging pairs.
The laboratory experience illustrates EVCA analysis of real charging partners.
Customer outcomeThe team describes EVCA as its most complete vehicle simulation, sniffer and man-in-the-middle system.
Frequently asked questions
Interoperability and charging analysis
What is charging interoperability testing?
Charging interoperability testing examines a specific real EV and EVSE during a charging session. It compares communication, low-level states, timing, electrical behaviour and both implementations’ reactions.
How does interoperability differ from conformance testing?
Conformance testing checks one implementation against defined requirements and test cases. Interoperability testing checks how two specific implementations interact. Both are needed to answer these different questions.
Why can individually compliant products still fail together?
Interpretations, optional behaviour, timing margins, certificate conditions, state transitions and error handling can differ. Their interaction may reveal a problem that a test of either implementation alone did not show.
Why is passive Man-in-the-Middle measurement useful?
Both real partners remain connected during the field capture. Passive Man-in-the-Middle measurement records the relevant layers on a common time base and preserves their actual interaction.
Why can communication traces alone miss an EV charging fault?
Compare a communication trace with measured voltage and current to check whether the electrical response matches the requested values. The trace alone cannot establish that match.
In the anonymised comemso precharge case, communication timing appeared unremarkable, while the measured EVSE voltage response did not match the requested battery voltage. An experienced product specialist identified this relationship by reviewing synchronised electrical and communication evidence. This was human analysis of one vehicle–charger pairing; the account does not establish that all faults have the same cause or diagnosis time.
Can a suspected cause be tested before software is changed?
Yes, where a released live validation method supports the required controlled change. The purpose is to observe cause and effect before implementing a correction in the EV or charging station.