VGA Extender (solved)

[DiTBho]

I need to prepare a very custom setup that includes a wild hack of one of IKEA's cheap standing tables.

The desk is equipped with two electric motors to move the work table (IKEA wood) vertically plus up to 18Kg or workload.

On the worktable I have to install three 22" NEC VGA LCDs (4Kg each), connected to a machine that I am building with such old video technology.

Don't ask me why, but I have to use CAT5 cables for the VGA, and here is where problems arises: inferences! VGA has three analog signals for the colors {R, G, B}, with two digital signals for timing  { V, H }, plus a simple i2c bus to query the monitor.

You can write these signals to a RJ45 connector, an use a CAT6 cable.
You can even remove the i2c bus and pair twist

Code: [Select]

RJ45.pin1: VGA.R \/\/ twisted pair0
RJ45.pin2: gnd   /\/\ Ethernet Cat6
RJ45.pin3: VGA.G \/\/ twisted pair1
RJ45.pin4: gnd   /\/\ Ethernet Cat6
RJ45.pin5: VGA.B \/\/ twisted pair2
RJ45.pin6: gnd   /\/\ Ethernet Cat6
RJ45.pin7: VGA.V \/\/ twisted pair3
RJ45.pin8: VGA.H /\/\ Ethernet Cat6
(idea for a VGA-to-RJ45 adapter)

with R.gnd = G.gnd = B.gnd = gnd (not a good idea, but that's it)

I built one of these VGA-to-RJ45 adapter and it helps a bit with the two motors, but ... since it's a "passive solution", I wonder if there is a better one

- true differential pairs via differential OA? (still analog, but it should be less weak about peaks)
- VGA over Ethernet 100BaseT (copper PHY)? (digital solution)
- VGA over Ethernet 100BaseSX (optical fiber)? (optical digital solution, virtually nothing can disturb light)

The VGA cables are only 4 meters long, but they all go together with the 230V power cables, through the same conduit.

Code: [Select]

.                                 ______
                                 |      |
Video1  ===========VGA===========| LCD1 |  ______
230V    ---------- 230V ---------|______| |      |
Video2  ===========VGA====================| LCD2 |  ______
230V    ---------- 230V ------------------|______| |      |
Video3  ===========VGA=============================| LCD3 |
230V    ---------- 230V ---------------------------|______|
230v    ---------- 230v --------------------
                                            \
                                            |
                                  ---------------------
                                 /                     \
                                 |                     |
                               MotorL                MotorR



Code: [Select]

    _______________  _______________  _______________
   |               ||               ||               |
   |               ||               ||               |
   |     22inc     ||     22inc     ||     22inc     |
   |               ||               ||               |
   |_______________||_______________||_______________|
                           | |
                          _____
Any experience? 

[darkspr1te]

I need to prepare a very custom setup that includes a wild hack of one of IKEA's cheap standing tables.

The desk is equipped with two electric motors to move the work table (IKEA wood) vertically plus up to 18Kg or workload.

On the worktable I have to install three 22" NEC VGA LCDs (4Kg each), connected to a machine that I am building with such old video technology.

Don't ask me why, but I have to use CAT5 cables for the VGA, and here is where problems arises: inferences! VGA has three analog signals for the colors {R, G, B}, with two digital signals for timing  { V, H }, plus a simple i2c bus to query the monitor.

You can write these signals to a RJ45 connector, an use a CAT6 cable.
You can even remove the i2c bus and pair twist

Code: [Select]

RJ45.pin1: VGA.R \/\/ twisted pair0
RJ45.pin2: gnd   /\/\ Ethernet Cat6
RJ45.pin3: VGA.G \/\/ twisted pair1
RJ45.pin4: gnd   /\/\ Ethernet Cat6
RJ45.pin5: VGA.B \/\/ twisted pair2
RJ45.pin6: gnd   /\/\ Ethernet Cat6
RJ45.pin7: VGA.V \/\/ twisted pair3
RJ45.pin8: VGA.H /\/\ Ethernet Cat6
(idea for a VGA-to-RJ45 adapter)

with R.gnd = G.gnd = B.gnd = gnd (not a good idea, but that's it)

I built one of these VGA-to-RJ45 adapter and it helps a bit with the two motors, but ... since it's a "passive solution", I wonder if there is a better one

- true differential pairs via differential OA? (still analog, but it should be less weak about peaks)
- VGA over Ethernet 100BaseT (copper PHY)? (digital solution)
- VGA over Ethernet 100BaseSX (optical fiber)? (optical digital solution, virtually nothing can disturb light)

The VGA cables are only 4 meters long, but they all go together with the 230V power cables, through the same conduit.

Code: [Select]

.                                 ______
                                 |      |
Video1  ===========VGA===========| LCD1 |  ______
230V    ---------- 230V ---------|______| |      |
Video2  ===========VGA====================| LCD2 |  ______
230V    ---------- 230V ------------------|______| |      |
Video3  ===========VGA=============================| LCD3 |
230V    ---------- 230V ---------------------------|______|
230v    ---------- 230v --------------------
                                            \
                                            |
                                  ---------------------
                                 /                     \
                                 |                     |
                               MotorL                MotorR



Code: [Select]

    _______________  _______________  _______________
   |               ||               ||               |
   |               ||               ||               |
   |     22inc     ||     22inc     ||     22inc     |
   |               ||               ||               |
   |_______________||_______________||_______________|
                           | |
                          _____
Any experience? 

You maybe have to use STP , Shielded Twisted pair CAT5 instead of UTP un-shielded twisted pair.
Another technology i've used on long vga runs is balon boxes like this one on amazon [url=https://www.amazon.com/Black-Box-Display-Balun-Male/dp/B00C8OL3OS]https://www.amazon.com/Black-Box-Display-Balun-Male/dp/B00C8OL3OS] [url]https://www.amazon.com/Black-Box-Display-Balun-Male/dp/B00C8OL3OS]https://www.amazon.com/Black-Box-Display-Balun-Male/dp/B00C8OL3OS]https://www.amazon.com/Black-Box-Display-Balun-Male/dp/B00C8OL3OS] [url]https://www.amazon.com/Black-Box-Display-Balun-Male/dp/B00C8OL3OS  while this helps it's not substitute for quality STP and keep power keep wires far away and if possible in shielded casing until last inch.


darkspr1te

[DiTBho]

Yes, Shielded Twisted pair CAT5/6.

[DiTBho]

Code: [Select]

RJ45.pin1: VGA.R \/\/ twisted pair0
RJ45.pin2: gnd   /\/\ Ethernet Cat6
RJ45.pin3: VGA.G \/\/ twisted pair1
RJ45.pin4: gnd   /\/\ Ethernet Cat6
RJ45.pin5: VGA.B \/\/ twisted pair2
RJ45.pin6: gnd   /\/\ Ethernet Cat6
RJ45.pin7: VGA.V \/\/ twisted pair3
RJ45.pin8: VGA.H /\/\ Ethernet Cat6
RJ45.Shield ----------- Cat6.Shield

is this wiring better? or doesn't it help?

[Ian.M]

Nothing you do to the 8P8C ('RJ45') pin order will have a significant effect on the signal quality, provided you don't split pairs, so you might as well stick to standard Ethernet pin order so you can use off-the-shelf cables.

However decent quality VGA cables have three individually shielded 75 ohm miniature coax cables for the RGB signals, + an overall double-braid or braid over foil screen.

CAT5/CAT6 twisted pair is nom. 100 ohms impedance, and is far more susceptible to EMI even if you use STP, and baluns to match the impedance and keep the signal return paths down the same twisted pair as each signal.

...
Don't ask me why, but I have to use CAT5 cables for the VGA, and here is where problems arises: inferences! ...

Really? or is it just far far far more convenient to use CAT5/CAT6?

Using real fully screened VGA cable with restricted access would probably involve cutting the plug off one end, then fitting a new one after threading it through, which is an expensive PITA even if you have the correct crimp tooling for DE-15 connectors (and a far greater PITA if you have to use a solderable DE-15 connector), but its not impossible.   Impossible would be if you couldn't accommodate the OD of decent quality VGA cable.

[DiTBho]

Nothing you do to the 8P8C ('RJ45') pin order will have a significant effect on the signal quality, provided you don't split pairs, so you might as well stick to standard Ethernet pin order so you can use off-the-shelf cables.

Ok

However Decent quality VGA cables have three individually shielded 75 ohm miniature coax cables for the RGB signals, + an overall double -braid or braid over foil screen.

CAT5/CAT6 twisted pair is nom. 100 ohms impedance, and is far more susceptible to EMI even if you use STP, and baluns to match the impedance and keep the signal return paths down the same twisted pair as each signal.

OK, now I understand why. Thanks 

Really? or is it just far far far more convenient to use CAT5/CAT6?

The diameter of the conduit does not allow to pass three VGA shielded cables shaft together with four 230V cables.

CAT5/6 have a smaller diameter, and look decent enough. Yes, here it's a matter of convenience; SC optic cables have smaller diameter, unfortunately VGA<=>optic converters are very expensive, 130 UKP each.

If they cost less, I would have no doubt in using optical cable for video signals 

Code: [Select]

.                                                   ______
                                                   |      |
Video1  VGA_to_Optic====fiber_glass====Optic_to_VGA| LCD1 |  ______
230V    ---------- 230V ---------------------------|______| |      |
Video2  VGA_to_Optic==========fiber_glass=======Optic_to_VGA| LCD2 |  ______
230V    ---------- 230V ------------------------------------|______| |      |
Video3  VGA_to_Optic================fiber_glass==========Optic_to_VGA| LCD3 |
230V    ---------- 230V ---------------------------------------------|______|
230v    ---------- 230v --------------------
                                            \
                                            |
                                  ---------------------
                                 /                     \
                                 |                     |
                               MotorL                MotorR


Using real fully screened VGA cable with restricted access would probably involve cutting the plug off one end, then fitting a new one after threading it through, which is an expensive PITA even if you have the correct crimp tooling for DE-15 connectors (and a far greater PITA if you have to use a solderable DE-15 connector), but its not impossible.   Impossible would be if you couldn't accommodate the OD of decent quality VGA cable.

I have no crimping tools. Umm, I might buy some 

[DiTBho]

Code: [Select]

.                                                   ______
                                                   |      |
Video1  VGA_to_udp/ip=====100BaseT====udp/ip_to_VGA| LCD1 |  ______
230V    ---------- 230V ---------------------------|______| |      |
Video2  VGA_to_udp/ip===========100BaseT=======udp/ip_to_VGA| LCD2 |  ______
230V    ---------- 230V ------------------------------------|______| |      |
Video3  VGA_to_udp/ip=================100BaseT==========udp/ip_to_VGA| LCD3 |
230V    ---------- 230V ---------------------------------------------|______|
230v    ---------- 230v --------------------
                                            \
                                            |
                                  ---------------------
                                 /                     \
                                 |                     |
                               MotorL                MotorR




VGA_to_udp/ip: grab VGA @ 30fps, H264 encode, transmit(udp/ip)
udp/ip_to_VGA: receive(udp/ip), H264 decode, shot VGA @ 30fps

This would also be interesting, it uses 100BaseT(copper) instead of 100BaseSX (optic).
I cannot find decent products.



I will try with "Baluns", first.

[Ian.M]

Could you get three VGA cables through the conduit if you only had one power cable through it?  If so, split the power top-side!

[DiTBho]

Could you get three VGA cables through the conduit if you only had one power cable through it?

Unfortunately no 

[NiHaoMike]

How about convert the VGA to HDMI and then use HDMI over CAT6 adapters?

[Berni]

How about convert the VGA to HDMI and then use HDMI over CAT6 adapters?

Yep convert it to HDMI and send that trough Ethernet cables. It works pretty well and you don't get any extra input lag since the data is being converted and sent live.

DisplayPort can also run multiple monitors over a single cable, but that would likely require the source to be a PC graphics card.

[DiTBho]

How about convert the VGA to HDMI and then use HDMI over CAT6 adapters?

It's expensive.

I have already tried several VGA-to-HDMI converters from Amazon, things like the GANUA are cheap 8-15 Euro but don't offer decent quality, the convert that actually does the job ... costs 110 euro, and a Couple of RX/TX HTMI-to-from-ethernet cost 120 euro.

120 Euro RX/TX HDMI-to/from-ethernet
110 Euro VGA-to-HDMI
-----------------------------------------------------
230 Euro per VGA line

For qty=3, it will cost 690 Euro !!! crazy!!!

[mariush]

One of the things you could do is to modify the monitor's power supply to work on DC.

If they're old monitors with pre-led (CCFL or whatever it's called) backlight, then the monitor will have a 230v to 12-20v power supply and from that voltage, there's gonna be 5v and 3.3v produced for the display board.
The backlight will usually work with as little as 10v, and there's also universal CCFL driver boards on eBay that can work with 10v or more... but they usually make the monitor power supply output 12-20v to reuse it for headphone / speaker amplifiers as well.

So basically what I'm trying to say is that you could hack the monitor to add a DC barrel jack connector and inject 12v...18v from a laptop adapter type of power supply directly AFTER the AC to DC conversion, and this would allow you to use much thinner DC power cables instead of 230v IEC standard (like on computer power supply) cables. Making room for other cables in that channel.

As for other ideas, they make flat HDMI cables
https://www.amazon.com/Flat-HDMI-Cable-20-Supports/dp/B074N6XFF7/  and they also make flat ethernet cables
https://www.amazon.com/Ethernet-Internet-Network-Computer-Connectors/dp/B00WD017BG/

If those monitors have DVI in the back, you could use a passive 2-3$  HDMI-DVI to make the monitor accept HDMI cable and you could use HDMI ... and being digital, the signal should be less sensitive to noise.  You could use a cheap vga to hdmi converter on the computer side if the signals are analogue in the first place.

[DiTBho]

One of the things you could do is to modify the monitor's power supply to work on DC.

If they're old monitors with pre-led (CCFL or whatever it's called) backlight, then the monitor will have a 230v to 12-20v power supply and from that voltage, there's gonna be 5v and 3.3v produced for the display board.
The backlight will usually work with as little as 10v, and there's also universal CCFL driver boards on eBay that can work with 10v or more... but they usually make the monitor power supply output 12-20v to reuse it for headphone / speaker amplifiers as well.

So basically what I'm trying to say is that you could hack the monitor to add a DC barrel jack connector and inject 12v...18v from a laptop adapter type of power supply directly AFTER the AC to DC conversion, and this would allow you to use much thinner DC power cables instead of 230v IEC standard (like on computer power supply) cables. Making room for other cables in that channel.

Nice idea. I will think about this.

As for other ideas, they make flat HDMI cables [...]  and they also make flat ethernet cables

Yup. I have just ordered a couple of flat Ethernet cables for testing.

If those monitors have DVI in the back, you could use a passive 2-3$  HDMI-DVI to make the monitor accept HDMI cable and you could use HDMI ... and being digital

Yup, my three LCDs have { VGA, DVI-D, DP } ports. I have also already ordered DVD-D-to-HDMI adapters (8 euro for a couple - gold contacts - so they said, we will see).

Here you mean: buy qty3 VGA-to-HDMI adapter (3x110 = 330 euro) and save half the money.
Great idea! 

[Berni]

Yup, my three LCDs have { VGA, DVI-D, DP } ports. I have also already ordered DVD-D-to-HDMI adapters (8 euro for a couple - gold contacts - so they said, we will see).

Here you mean: buy qty3 VGA-to-HDMI adapter (3x110 = 330 euro) and save half the money.
Great idea! 

Then why ware you even using VGA on the monitor end? Especially if you care about image quality since it adds an extra digital to analog to digital conversion.

Is there a way to also sidestep VGA on the video source side?

[mariush]

Here you mean: buy qty3 VGA-to-HDMI adapter (3x110 = 330 euro) and save half the money.
Great idea! 

No, there's also cheap vga to hdmi converters ... never used them but they could be an option if it's a must :

https://www.amazon.com/QGeeM-Converter-adaptador-Computer-Projector/dp/B083K83NNX/

https://www.amazon.com/dp/B071SHJ1S3/

Not sure about the quality of the image but I imagine it wouldn't be awful.

[m k]

I was wondering how this VGA over 100M Ethernet is operating since VGA pixel rate is 18M and so bitrate is 440M for truecolor.

Technically frame is not a picture so is it interlaced and so 15 packed pics/sec?
Not exactly a movie quality and mouse update can be a problem.

[DiTBho]

Then why ware you even using VGA on the monitor end?

Because on the host side the video graphic is VGA.

[DiTBho]

Converting VGA (host) to HDMI (LCD) is an option (via DVI-D-to-HDMI), but it's not cheap: I have tried a lot of converters, the only VGA-to-HDMI that actually does the job costs 110 euro.

I am considering this solution, anyway. Not cheap, but with flat-HDMI cables it looks an achievable sub-optimal one.

[mariush]

Wouldn't it be cheaper to add a video card in the system, with 2-3 digital outputs?

and i find it hard to believe you found no reliable vga to dvi/hdmi converter.. did you try products like the ones I linked to a few posts above?

[DiTBho]

No, there's also cheap vga to hdmi converters ... never used them but they could be an option if it's a must :

You never used, so WHY do you suggest random things?
I have already tested many with no decent result with chap converters.

[DiTBho]

Wouldn't it be cheaper to add a video card in the system, with 2-3 digital outputs?

Off course, I cannot!

[DiTBho]

Solved. I contacted a company and bought three second hand VGA-to/from-optic units, 60 euro each.
Not bad. Plus 40 euro for SC-SC optic cables