Video · Practical guide
AV-HS410: input frame sync, reference and video delay
If the picture rolls or will not stay stable, record the symptom before changing its size. A fixed crop at the edges calls for a different check. For a presentation from a computer, identify the format reaching the switcher, then check how that input is synchronized.
The computer reaches the switcher, but the picture is unstable
For the AV-HS410N, the Operations and Settings manual VQT3U71A-1(E), pp. 73–75 gives this sequence: Input > Input, Select with [F2], then FS with [F1] and the FS value with [F2]. Frame sync stays enabled on the DVI input. The AV-HS410E basic manual, VQT3U72-2, describes the system formats; record your unit's suffix and version before using these controls.
Off air, select the physical input receiving the computer. Record its initial state and first check that the actual source arrives in a supported format. If the test requires an unsynchronized source, compare with FS set to On. Watch for picture stability, motion and switching to that source; save a sample before and after. If the problem persists, check the preceding stage and the received format. This alone does not establish a cable or switcher fault.
Use a test pattern with an edge border and a moving clip to assess picture size and stability separately. If a fixed crop remains after stability is restored, continue checking framing with the converter guide.
Switcher reference and MD-HX SDI reference: identify the signal
The AV-HS410E Basics manual VQT3U72-2, p. 29 describes the REF connector: in external synchronization mode it has loop-through and requires 75-ohm termination when the output is unused; in internal mode both connectors output BB. The AV-HS410N manual VQT3U71A-1(E), p. 92 places Sync and Gen Lock under System > Reference. Locked can apply to either internal or external reference, so also check the selected mode.
The MD-HX has a separate setting: DUC REF in manual 1.5, printed p. 4 / PDF p. 5, or DUC/TPG REF in manual 2.0, printed p. 6 / PDF p. 7. SDI IN selects its SDI video input as the scaler reference. Do not connect BB or tri-level to that port just because it uses a BNC connector; it is not documented as an analog REF input.
On the worksheet, draw two paths: the computer content and the reference signal. If you plan to feed SDI video from a switcher output to the MD-HX, identify the output, format and signal presence. Check HDMI as the picture source and Scaler as the output source separately. Then check the receiver. The manual documents the controls; this connection still needs to be tested in the actual setup.
When the AV-HS410 uses external reference, record the generator, signal, system format and termination. If UnLock appears, check that path before adjusting phase. Do not change the system-wide reference mode during the event to fix a single input: prepare the comparison and a way to restore the initial settings.
| Stage in the signal path | Check | Result to record |
|---|---|---|
| Content → converter | Input, scaler source and output in use. | Actual source visible and received format. |
| SDI video → MD-HX | DUC REF or DUC/TPG REF, connector and signal presence. | Selected reference and a sample from the receiver. |
| Reference → AV-HS410 | System > Reference, Sync, Gen Lock and termination. | Selected mode and Locked or UnLock. |
| Source → switcher input | Physical input, format and FS. | Stability and switching to that source. |
FS cannot be turned Off, or the screen is delayed: check phase and signal path
On the AV-HS410N, VQT3U71A-1(E), pp. 75 and 92, setting Output Phase to 0H requires FS to remain enabled. An unavailable Off option does not by itself indicate a fault. Check that setting and the input type before looking for another menu.
The HD table on p. 94 distinguishes FS, mode, reference, output phase and processing. It also identifies additional delay from DVE, PinP and multiview. Multiview alone therefore cannot establish that the program output has the delay seen on the monitor. The manual's values describe specific conditions; they are not measurements of your screen.
For an in-room screen showing a camera feed, prepare a test with a visible, repeatable change. Compare the output feeding the room with multiview and the other stages in the diagram. Keep the format, content and monitor unchanged during each comparison, and change one stage at a time. Record the camera, converter, input, effect, output and screen processor.
Do not disable FS simply to reduce delay. First check whether the source is synchronized and which output phase the system requires. Sign-off needs a record of stability and delay for each destination. This guide provides a test procedure, not measured results from a GLMedia setup.
| Off-air comparison | Keep unchanged or record | What to observe |
|---|---|---|
| Program versus multiview | Same source and format; identify both outputs. | Whether the difference comes from the monitoring path. |
| Signal path with and without an effect, if the setup allows it | Input, destination and saved initial settings. | Visible change when that stage is altered. |
| In-room screen versus the signal before its processor | Repeatable content and identified destinations. | Where delay is added; stability of each path. |
Record the test for each input and destination
Use the switcher synchronization worksheet. It is blank: record the initial settings, one variable per test, a sample, the result and the restored state. Distinguish the manufacturer's instructions from a proposed test and a test actually completed in your setup.
The camera HDMI guide helps separate the recorded file from the live signal. To plan the screen, recording and stream as separate destinations, see conference video with LED, recording and streaming. Include those signal paths when requesting video processing.
Frequently asked questions
Can I rule out synchronization issues if resolution and frame rate match?
You still need to check synchronization at that input. Record the received format, FS and reference in use. For the AV-HS410, follow its documented controls and test your source off air.
Where do I check FS for an AV-HS410 SDI input?
In the AV-HS410N manual VQT3U71A-1(E), select the input with Input > Input > Select [F2], open FS with [F1] and select FS with [F2]. First confirm the selected connector. Save the initial setting and observe the actual source when testing On. If the problem persists, continue checking the converter and received format.
Why will the AV-HS410 not let me set FS to Off?
Check Output Phase: at 0H, the manual requires FS to remain enabled. FS also stays enabled on the DVI input. Identify the input and phase before interpreting an unavailable control. Changing phase affects the system output, so prepare any comparison off air and keep a way to restore the initial state.
Does a Locked Gen Lock status mean all computers are synchronized?
That status describes the switcher's synchronization with the selected reference. Read Sync to see whether it uses internal or external reference, and check each input separately. A computer still needs its signal path, format and FS checked. The useful test is whether that source stays stable and can be switched in the intended setup.
Can I feed BB from the AV-HS410 into the MD-HX SDI IN as a reference?
The MD-HX SDI IN is an SDI video input. Its 1.5 and 2.0 manuals allow it to be selected as the scaler reference; they do not document it as an analog BB or tri-level input. Identify the signal type before connecting it. Picture source selection and Scaler output selection remain separate controls.
Is the delay I see in multiview the same as the delay on the in-room screen?
Compare the actual outputs. The AV-HS410N manual distinguishes multiview, effects and output phase, and documents additional processing. Include converters and the screen processor in your diagram. Measure or record a repeatable comparison for each destination before attributing all delay to frame sync; this guide contains no measurements from your setup.
How do I distinguish a fixed crop from a rolling input picture?
Compare a test pattern with an edge border and a moving clip on the output intended for the event. Record size and stability separately. If the picture stays stable but edges are missing, continue checking framing at the source, converter and destination.
How should I test an AJA FS2 with a Carbonite Black Legacy?
First confirm the exact models, versions, supported formats and initial settings in the applicable manuals. Prepare an off-air test that changes only one variable, and check the actual source at its destination before accepting the setup. This guide does not provide a configuration for that combination or establish that an AJA FS2 will fix the problem.
Sources and manuals
- Panasonic AV-HS410N — Operations and Settings, VQT3U71A-1(E); pp. 73–75, 92–94: Input, FS, Reference and phase. PDF hosted under hs410_ver201; installed firmware not verified.
- Panasonic AV-HS410E — Basics, VQT3U72-2; pp. 9, 29 and 36: formats, REF, termination and specifications. This basic manual alone does not establish that model N menus apply.
- Decimator MD-HX — Operating Manual 1.5, ©2015–2023, printed pp. 3–4 / PDF pp. 4–5: scaler source and reference. Check the actual hardware series and firmware.
- Decimator MD-HX — Operating Manual 2.0, ©2015–2026, CLD/E/F, printed pp. 5–6 / PDF pp. 6–7: DUC/TPG and outputs.