A 10-second capture of the sample substation compared with the planned streams: a missing merging unit, a confRev mismatch, an unknown test publisher with a clashing APPID, lost GOOSE and unsynchronised samples.
| Capture | Sample capture generated from the project: 40 099 frames in 10 s (SV 39 997, GOOSE 61, MMS 31, PTP 10) |
| Plan | 4 GOOSE and 2 SV streams from the VLAN & multicast table |
Open SCL NetStudio ▸ Capture analyser ▸ Load sample capture.
| Planned stream | Seen | Result |
|---|---|---|
| GOOSE P132_Q01/GCB_TRIP · 0001 | Yes | Matches |
| GOOSE P132_Q02/GCB_TRIP · 0002 | Yes | Matches |
| GOOSE P87T_T1/GCB_DIFF · 0003 | Yes | confRev 2 (plan 1) |
| GOOSE BCU_J01/GCB_IL · 0004 | Yes | Matches |
| SV MU_Q01/MSVCB01 · 4001 | Yes | VLAN 0 (plan 11) |
| SV MU_T1/MSVCB01 · 4002 | No | Missing |
| — (not in the project) | TEST_IEDLD0/LLN0$GO$gcb01 · 0001 | Unexpected |
P132_Q01: stNum jumped 6 → 8 — one state change was never seen. P132_Q02: no message for 3 000 ms against a TAL of 2 000 ms — subscribers would declare the stream lost — and sqNum jumped 6 → 9. TEST_IED publishes APPID 0001, the same as P132_Q01's trip, untagged and with the test flag set.
MU_Q01: 3 samples missing before smpCnt 2003, and smpSynch = 0 in 1 599 samples (not time synchronised). It is only priority-tagged (VLAN 0), so it is not in the planned SV VLAN 11.
One TCP retransmission between the gateway (10.13.0.11) and P132_Q01 (port 102): packet loss or congestion on the station bus.
| Check | Requirement | Actual | Status |
|---|---|---|---|
| All planned streams present | 6 of 6 | 5 of 6 (MU_T1 missing) | ✗ FAIL |
| No unknown publishers | None | TEST_IED with APPID 0001 | ✗ FAIL |
| GOOSE continuity | No lost state changes, TAL respected | stNum gap; TAL exceeded | ✗ FAIL |
| SV synchronisation | smpSynch = 2 | 0 in 1 599 samples | ✗ FAIL |
Key insight: A capture compared with the plan finds the problems that each device's own configuration tool cannot: missing and unknown publishers, address clashes between vendors, and devices that are configured correctly but not on the right VLAN or clock.
Every input in this example is editable in the live calculator — no signup needed.
Open SCL NetStudio (IEC 61850 network design) calculator →On a mirror port or TAP that receives the multicast traffic of interest — for sampled values, on the process bus switch; for GOOSE, on the station bus. Capture for long enough to include a few state changes.
SCL NetStudio checks the capture against the network plan. The GOOSE & SV Capture Analyzer runs 86 detailed conformance checks per frame with clause references; the two complement each other.