Subject:
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Re: Re[2]: phone cord length
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Tue, 4 Mar 1997 13:47:20 GMT
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Original-From:
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Mike Ross <mross@outland+StopSpam+.jsc.nasa.gov>
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Viewed:
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1620 times
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On Tue, 4 Mar 1997, Richard Whitehead wrote:
> TTL does NOT go down that line, it is RS232 which is commonly used at
> up to 50 feet. However, you might need to use a shielded cable if you
> use a lead longer than about 10 feet.
No, the MAX232 chip on the charger board converts from 12V RS232 coming
out of the serial port to TTL level RS232. What goes down the line to the
Handyboard is 5V RS232, which goes straight into the HC11 and at only 5V
levels is more susceptible to noise. I use a 6 foot unshielded phone cord
in a noisy environment with no problems.
-mike
* Michael L. Ross/C33 | Lockheed Martin Eng & Sci Svcs Co. ****
* Robotics Department | 2400 Nasa Rd. 1, Houston, TX 77058*****
* (281)333-7094; (281)333-6071 fax* #include <disclaimer.h>*
* Finger me for my public key. mross@outland.jsc.nasa.gov ****
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Message has 2 Replies:
 | | Re: Re[2]: phone cord length
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| Speaking of noisy lines, I was thinking of getting one of those telephone cords that's coiled helix-like to colapse the wire. Now that we're discussing this topic, I am wondering if this cord would effect the electronics. The thought came up to me (...) (28 years ago, 5-Mar-97, to lugnet.robotics.handyboard)
| | | Re: Re[2]: phone cord length
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| Don't those tend to have swapped conductors too? I thought that the receiver cords were slightly different from the other cords. You might have to crimp new connectors on the end. -Jeremy (...) ___...___ Jeremy Green jag@world.std.com (...) (28 years ago, 5-Mar-97, to lugnet.robotics.handyboard)
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Message is in Reply To:
| | Re[2]: phone cord length
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| TTL does NOT go down that line, it is RS232 which is commonly used at up to 50 feet. However, you might need to use a shielded cable if you use a lead longer than about 10 feet. Richard (28 years ago, 4-Mar-97, to lugnet.robotics.handyboard)
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