knight3
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250 ft cable: Use VNC or Monitor?

Sat Feb 01, 2020 5:57 am

Hello, I have a question regarding an idea I have that may or may not be viable. My senior design team is using a RPi for a robot that will be going through tunnels that can be 250 ft in length and we want access to the desktop. I have it initially set up to have it connect with a separate laptop using VNC and a long ethernet cable. I would like to know, however, if it is feasible to use that long ethernet cable we have to connect to a monitor that either has an ethernet input or can convert to HDMI and connect straight to the laptop. I thought of this to see if lag time would be reduced by this method. Any suggestions/comments on this idea would be very appreciated.

drgeoff
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Re: 250 ft cable: Use VNC or Monitor?

Sat Feb 01, 2020 12:14 pm

knight3 wrote:
Sat Feb 01, 2020 5:57 am
... use that long ethernet cable we have to connect to a monitor that either has an ethernet input or can convert to HDMI and connect straight to the laptop.
I don't understand that.

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DougieLawson
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Re: 250 ft cable: Use VNC or Monitor?

Sat Feb 01, 2020 12:22 pm

Use VNC, it's a TCP/IP application so will run over an ethernet connection (up to 100 metres ~300 feet).
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PhatFil
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Re: 250 ft cable: Use VNC or Monitor?

Sat Feb 01, 2020 12:28 pm

I suspect a spam post, senior research team? and no one can use google?

just in case im wrong..
https://www.google.com/search?q=max+net ... e&ie=UTF-8
The maximum length you can run Cat5, Cat5e, Cat6 and Cat6a cable is 100 meters or 328 feet. If you require a longer run, you will need to put an active component, such as a router, in-between the signals.
so if you do have issues stick a battery powered hub or switch 1/2 along the length..

knight3
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Joined: Sat Feb 01, 2020 5:48 am

Re: 250 ft cable: Use VNC or Monitor?

Sat Feb 01, 2020 4:44 pm

Thank you for the comments. I think I know now what we need to do. Just for clarification too, its part of our undergraduate senior design project.

W. H. Heydt
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Re: 250 ft cable: Use VNC or Monitor?

Mon Feb 03, 2020 3:23 am

knight3 wrote:
Sat Feb 01, 2020 4:44 pm
Thank you for the comments. I think I know now what we need to do. Just for clarification too, its part of our undergraduate senior design project.
When you write this up for your instructor be sure to mention that you had to seek help from a support forum to figure out how to do that.

PhatFil
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Re: 250 ft cable: Use VNC or Monitor?

Mon Feb 03, 2020 4:47 am

W. H. Heydt wrote:
Mon Feb 03, 2020 3:23 am
knight3 wrote:
Sat Feb 01, 2020 4:44 pm
Thank you for the comments. I think I know now what we need to do. Just for clarification too, its part of our undergraduate senior design project.
When you write this up for your instructor be sure to mention that you had to seek help from a support forum to figure out how to do that.
Indeed! Finding a relevant technical forum will score you extra credit, include a link as proof to make sure you get it..

IanS
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Re: 250 ft cable: Use VNC or Monitor?

Wed Feb 05, 2020 11:20 am

250 feet of cabling is a serious drag on a robot. You should be considering the physical properties of the wire too. How heavy is it? How easily does it go around corners? (Assuming it is not just a straight pipe you are going down.) How can you avoid getting tangled when you manoeuvre back through an area the cable already goes through?
That kind of length is nothing too unusual for a network cable, but is a long way for a video lead. The HDMI standard does not specify a maximum length, but 15m is generally considered the limit for maintaining good quality. A quick search did not find any leads over 20m. You might find that the only video leads good for that kind of distance are high quality thick cables, and so difficult to drag along.

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