Reply to "Serial Data over copper pairs"

mikewalkerMember

James is spot on with this.

We found at Lake Louise that we could send RS-485 serial data over 3000 meters with no problem, however, you'll need to terminate the twisted pair.

Don't get scared, but you should add (about) a 600 ohm resistor at each end to balance the line. While we found that it worked 'ok' without the 600 terminator, (it would drop 1 in 10 packets), it was so much better with the 600 ohm resistor (1/8 watt is OK).

All you do is attach the resistor to both leads (you'll need one at each end--the electronic term is 'in parallel'). This balances the line at each end and prevents electronic ringing.

Then again, check RS-485 line driver you buy. It may have an internal terminator that you can switch in and out.

Mike

12/6/068:24 AM

<ul id="{%=id%}ButtonGroup" class="button-group h-popup-buttons even-button-group even-1">
    <li id="{%=id%}Okay_buttonContainer"><a id="{%=id%}Okay" href="javascript:void(0);" class="button success no-margin-bottom h-alert-modal-ok-button" role="button">OK</a><script type="text/javascript">
        (function() {
            function {%=id%}Okay_click(event, data) {
            {%=id%}Popup.hide();
        }
        
                $('#{%=id%}Okay').on('click', {%=id%}Okay_click);
        })();
    </script></li></ul><a href="javascript:void(0);" class="close-reveal-modal" aria-label="Close Modal">&#215;</a><div class="last-modal-focus focus-utility-element" tabindex="0"></div>
</div>
<script type="text/javascript">
        (function() {
            {%=id%}Popup = new SS.Popup.ModalPopup('{%=id%}');
        })();
    </script>

Skip to main content

Membership Required

Remove From Your Block List

Manage Follow Preferences

Block

Please wait...