Low-voltage switchgear and controlgear - Controller-device interfaces (CDIs) - Part 2: Actuator sensor interface (AS-i) (IEC 62026-2:2008, modified + A1:2019); German version EN 62026-2:2013 + A1:2019; Corrigendum 1
1Key Takeaways
This standard applies for a method of connecting switching elements, such as low-voltage switchgears and controlgears standardized within IEC 60947, and controlling devices. It may also be applied for connecting other devices and elements.
2Expert Interpretation
This article provides a professional interpretation of the revised document (VDE 0660-2026-2 Berichtigung 1) of the DIN EN 62026-2:2020-12 standard, focusing on the updated impedance test method for the AS-i controller-device interface, including key technical changes such as test circuit modification and measurement parameter adjustments.
Standard Revision Background
The February 2021 revision to DIN EN 62026-2 (VDE 0660-2026-2 Berichtigung 1) includes technical corrigenda for the AS-i (Actuator Sensor Interface) network test specification. This revision primarily involves revising the mathematical representation of the impedance measurement method and refining the test procedure.
Core revised content
| Original clause | Revised content | Technical impact |
|---|---|---|
| 9.4.1.2 Test circuit | Revised impedance calculation formula to |Z| = |U-| / |I-| | Unified AC parameter representation |
| 9.4.1.4 Test procedure | Clarified test frequency adjustment rules (±10kHz when resonance occurs) | Improve the reliability of anti-interference test |
| 9.6.3.1 General requirements | Specifies that the superimposed AC signal source impedance is R < 20Ω | ensuring signal source stability |
Detailed Explanation of Key Technical Changes
1. Updated Impedance Test Specifications
The revised clause 9.4.1.2 clarifies the use of absolute vector notation to represent AC parameters (U- and I-) to avoid misunderstandings caused by non-standard notation in the original text. This revision aligns with IEC 62026-2:2008+A1:2019.
2. Resonance Frequency Test Requirements
Added supplementary information to the test procedure in 9.4.1.4: When the AS-i device resonates within the 50-300kHz test frequency band, it must be retested within ±10kHz of the resonance point. This requirement is achieved through the following steps:
- Use an AC voltage signal source to superimpose a 6V peak-to-peak signal
- Monitor the sudden change point of the current waveform
- Record the resonant frequency and adjust the test point
Implementation Recommendations
Test Equipment Configuration
The following configuration is recommended to meet the revised requirements:
- Signal source output impedance: ≤1Ω (basic test) / ≤20Ω (master test)
- Current clamp bandwidth: ≥500kHz
- Oscilloscope sampling rate: ≥5MS/s
Document Management
According to VDE recommendations, "Note 2021-02 revised document" should be marked on the cover of the original standard document. Pay special attention to:
- Implementation of the test circuit diagram in Figure 99b
- Verification of the printed version of the formula
- Software update of the frequency sweep program