Sony EVI-D70 Camera Control

[rubantin]

What about just running composite through the coax and using the cat5 to control... since I am only doing 470 lines of resolution with the cameras, would s-video give me any significant benefit?

[Aczlan]

Are you planning to run individual wires from the S-video on individual wires on the CAT5 cable? If so, I don't think that would work well. As I understand it, the S-video has two grounds and two signals lines (luminance and chroma)--the old Commodore Amiga signal scheme. Those signal lines are 75 ohm and need to be constant impedance down the line for proper signal transfer. There are 'balun' devices for sending composite over CAT5 with proper impedances and such, so I suspect there may be such devices available for sending S-video over CAT5. Most likely, they require at least two matched pairs.

There are such devices. We have had good luck with 2 pairs of these: http://www.knollsystems.com/prod-svideo.html. They are IR and S-Video only, but the quality is pretty good.

If you're lookin at five wires for the RS-422 control, that's most likely RX+, RX-, TX+, TX-, and ground. If so, you could use the COAX for that ground (and not use the COAX for anything else). Just make sure to connect the ground before connecting the signal lines (and disconnect in reverse order) and put each direction (RX vs TX) on one pair to avoid crosstalk with any analog signals in the CAT5. You might also look into running RS-485, which is a half-duplex (and more) protocol on top of RS-422, if the equipment is friendly to that arrangement.

IIRC, the EVI-D70 only supports RS-422 and RS-232, otherwise, that sounds good to me.

Combining analog signal and control in a single CAT5 _MAY_ introduce noise from the control bit stream into the analog signal, especially if any of the signals is not properly balanced or is not properly paired. Combining digital and analog grounds makes it very likely you will see noise injection. You might be lucky and find a combination that works for your installation, but YMMV.

Mixing digital and analog grounds is touchy (at best) in my limited experience... If you can get a demo of the system (or return it at no cost), I might try it, but I think you will have issues with it.

Eventually, and probably not many years distant, cameras will likely switch from analog output to IP output. If you can find a high enough quality USB camera, you could also consider a USB camera, a USB-over-IP device for the video signal, an RS-422-over-IP adapter for the controls, and an ethernet switch at the camera location. If needed, you could run class-2 DC power over the coax or maybe use POE (power over ethernet).

If you can live with IR control, the Knoll system I linked to above will give you S-Video and control over a single CAT5/6 cable.
We have been happy with it so far, but I am debating switching to serial control as IR gets twitchy when on zoom.

Aaron Z

[Paulbb1]

We have three cables coax to the camera composite output and Cat5e for s-video (using two MuxLab 500016 S-Video Videoease CAT5 Balun). Plugged into video capture card for best webcast video. composite is connected to building channel 5 for cultural hall, Primary and RS rooms. It works.

The third Cat5e cable is used for RS422 connection. Direct connect to the camera and the other end requires a Cat5e to RS422 serial port adapter (Http://www.hexin-technology.com). We tried to use the serial to USB adapter which didn't work. Going to try without USB adapter now that we have an older laptop with a 9 pin serial port.

The remote works well most of the time so there has not been a lot of pressure to getting it done.

[rmrichesjr]

What about just running composite through the coax and using the cat5 to control... since I am only doing 470 lines of resolution with the cameras, would s-video give me any significant benefit?

That would be the simplest option. In theory, using composite rather than S-video will give poorer quality. In practice, you might not be able to tell the difference. Most likely, most of the non-technical people wouldn't notice the difference.

[Aczlan]

That would be the simplest option. In theory, using composite rather than S-video will give poorer quality. In practice, you might not be able to tell the difference. Most likely, most of the non-technical people wouldn't notice the difference.

By the time the webcast box/software compresses the stream and the reciving computers decompress it, you will probbaly not be able to tell the difference.

Aaron Z

[rmrichesjr]

We have three cables coax to the camera composite output and Cat5e for s-video (using two MuxLab 500016 S-Video Videoease CAT5 Balun). Plugged into video capture card for best webcast video. composite is connected to building channel 5 for cultural hall, Primary and RS rooms. It works.

The third Cat5e cable is used for RS422 connection. Direct connect to the camera and the other end requires a Cat5e to RS422 serial port adapter (Http://www.hexin-technology.com). We tried to use the serial to USB adapter which didn't work. Going to try without USB adapter now that we have an older laptop with a 9 pin serial port.

The remote works well most of the time so there has not been a lot of pressure to getting it done.

Regarding the USB adapter that did not work well, were you using the USB to RS-422 or to RS-232? If you use a laptop's 9-pin serial port (RS-232), you'll need an RS-232 to RS-422 converter. As long as the CAT5 cable for RS-422 is used only for that and not for IP, you should just be able to wire it up to an appropriate connector, as long as the electronics on both ends does RS-422.

[russellhltn]

If you're lookin at five wires for the RS-422 control, that's most likely RX+, RX-, TX+, TX-, and ground.

I don't think there's any need for a ground line in RS-422. In fact it may introduce problems with the video. I'd be tempted to leave it out.

since I am only doing 470 lines of resolution with the cameras, would s-video give me any significant benefit?

A good question. The idea behind S-video is to avoid any degradation by trying to separate the two signals with a comb filter. (Which is necessary before the signal can be displayed.) But that only works if the two components are internally constructed to take advantage of that. To do that, the sender has to develop the two signals separately in it's internal process. (If the camera chip develops only composite, then there's a comb filter in the camera to create the S-video. In which case there's an advantage only if the camera has a superior filter to one in the receiver.) Likewise, the receiver has to be able to take advantage of the two signals and not just combine them back together.

I believe S-video was introduces with the SVHS VCRs because they stored the two signals separately on the tape and wanted to give the sharpest signal to the TV screen by bypassing the TV set's comb filter. But at the end of the day, it's still SD video. Perhaps a little crisper, but still SD.

But the best way to find out is run some tests using the equipment in question.

[Paulbb1]

Regarding the USB adapter that did not work well, were you using the USB to RS-422 or to RS-232? If you use a laptop's 9-pin serial port (RS-232), you'll need an RS-232 to RS-422 converter. As long as the CAT5 cable for RS-422 is used only for that and not for IP, you should just be able to wire it up to an appropriate connector, as long as the electronics on both ends does RS-422.

Your correct the PC board for connecting wires to 9 pin D connector is just that. It connects the wires and a RS-422 to RS-232 converter is required. ( http://www.hexin-technology.com/RS-232_ ... t-245.html )
Thank you for pointing that out. I will have to buy one. The Sony SW doesn't work with the USB adapter from my experience. But will SW work with a RS232 port? Anyone get it to work since 9 Pin serial ports are going away?

[russellhltn]

The Sony SW doesn't work with the USB adapter from my experience.

Getting any software to work with a USB serial port is a hit-or-miss affair. Many devices do not fully support all the signal lines. You can verify that by looking at any GPS forum. The trick is to find a brand of converter that works and stick with it. Surprisingly, some of the cheaper ones work best.

[Paulbb1]

Getting any software to work with a USB serial port is a hit-or-miss affair. Many devices do not fully support all the signal lines. You can verify that by looking at any GPS forum. The trick is to find a brand of converter that works and stick with it. Surprisingly, some of the cheaper ones work best.

Can we start a list of RS422 to USB converters that work with the Sony SW or the one talked about here in forum? Or does the Wiki have a list?