No signal detected

DVI2USB 3.0, SDI2USB 3.0 Setup, Kit, & Gear
1

Hello,

I have DVI2USB 3.0 and DVI2PCIe frame grabbers and I’m trying to setup them with my device.
I have an embedded device which generated LVDS video output.
setup is following:
device -> display
|
-> LVDS to DVI -> frame grabber

when using the device with its display - everything is fine - video is always displayed.
but when I connect the frame grabber - I do not get a signal in the epiphan tool.
Usually, It just say “No signal detected”
if I unplug-plug couple of times the DVI connected/USB, it’s gets “synched” and I see the video signal also in the epiphan tool.

What could be the problem?

same setup is tried with both DVI2USB and DVI2PCIe (latest drivers) - I always get the same result.
at first - no signal. after couple of unplug-plug - the signal comes

2

Hello,

Unfortunately our grabbers are not compatible with LVDS/Spread Spectrum signals. Interesting that you are able to make the signal come through after some unplug/replug cycles. Unfortunately we would not be able to provide any support for this use-case.

My apologies for this inconvenience. If you have further questions you can email us at info@epiphan.com and we will open a support ticket.

3

Hello Adam,

I have LVDS to DVI convertor board in between my device and the frame grabber…
I have seen such/similar setups working fine.

if I make it like this:
device -> LVDS to DVI board -> PC monitor - video signal is shown on the monitor

I have troubles only when connected to the frame grabber.

Thanks in advance!

4

What is the make and model of the LVDS to DVI adapter? I believe it would need to be an active adapter to change the signal enough to make it fully compatible.

5

it’s a Westar:

LVDS to DVI Converter Board
[https://www.westardisplaytechnologies.com/products/lvds-dvi-converter-board/]

6

Hmmm okay, thank you for that. I took a look at the specs and documentation and it does seem like the board should work, unfortunately we have never tested this board specifically to my knowledge.

A couple things I would check:

What is the resolution and refresh rate of the output of the board when used in conjunction with the LVDS source? I’m wondering if perhaps there is a resolution and/or refresh rate mismatch occurring here. I can see in the specs of the board that it can go up to 165mhz and that’s not something our grabbers would support I don’t think.

7

What is the resolution and refresh rate of the output of the board when used in conjunction with the LVDS source

1920 x 568 x 60Hz

I’m wondering if perhaps there is a resolution and/or refresh rate mismatch occurring here.

I was also thinking of the same… I was feeling that there is something wrong/corrupted with the video signals … but if I hook it up to its original display - it’s always shown perfectly…

8

That’s an odd resolution but it’s still within spec so it should work. Just to clarify, you mentioned that after you unplug and replug the source a number of times the signal does actually come through? Does it come through at the expected resolution and does it remain stable after?

9

Hi Adam,

after further testing/experimenting with some settings on the device side/SW, it turns out that the issue is due to spread spectrum.

if the spread spectrum is disabled at device side, the frame grabber is always detecting properly the video signal.

Is there any solution available for capturing video with DVI2USB 3.0 / DVI2PCIe from devices with enabled spread spectrum?

10

Unfortunately not, spread spectrum is not supported on any of our products. Apologies for this inconvenience!

11

ok, thanks for the support!