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Originally Posted by kamocat
So a twisted pairs help reduce interference between two signals in the same cable?
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Yes.
Quote:
Originally Posted by kamocat
That's interesting, but not what I'm looking for. It sounds like just shielding the cable is the correct approach here. Perhaps I need to pull out an O-scope and find out.
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It actually is a component of what you want. While it is likely that the CAN traffic coupling onto the serial wires is the source of your problems, you also don't want the serial TX coupling to the RX or vice versa. That's not as likely since the frequency is an order of magnitude lower than the CAN traffic, but if you're building a custom cable anyway, this can help. Shielding will help your use case more though, for sure.
Quote:
Originally Posted by kamocat
As far as types of shielding, what are my options?
I have some bonding braid I can slip around the 6 conductor ribbon cable. Assuming I've insulated the braid, why would I not want to do this?
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You can do that and it will probably be pretty effective, but also ugly and a bit unwieldy. Generally there are plenty of manufactured shielded cables out there that will do just great for your application. You can go with the 2 twisted pair as I described, or you will probably be fine with a simple shielded 3 conductor cable. Just don't be tempted to use the shield as the ground conductor for the serial port in a cable such as the one linked to earlier. As Alan suggested, only ground the shield at the DB9 end.
-Joe