A new question. If you have a short run to the first node even with changing the resistor and let's say at node 40 you need to have a 4-5 foot run before node number 41, will this be a problem? Or is the ringing only between the first node and ssc v2.
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to expand keith's question, does the ringing settle down after the first node?
Interesting questions. From what I see on the scope and experimentally, the answers are:
1) Once the data signal hits the first node, it is cleaned up, amplified and 're-broadcast'. You can have pretty ratty data into the node and a clean signal does come out. Though this output is based on what the node interpreted from the input. So if the data-in isn't interpreted correctly, you have a nice strong, but wrong, signal coming out. (This actually contradicts my earlier thought that the data is just 'piped through', so will try to find/edit that post)
2) The inter-node distance doesn't seem to have the same problem with ringing. I have an 8 foot gap set up here on the bench top and, while the signal does show some ringing, it's not nearly as bad as the SSC at even 2-3 feet, and the color changes are still being made 100% correct. Adding a 47 ohm resistor in that line damped the ringing, too, so I suspect dozens of feet might not be an issue.
I suspect the node input/output is matched for one-another, so not a lot of 'impedance mismatch' and a clearer signal transfer. Further the node output signal is stronger for some reason...seeing almost 5.7 volts peak between nodes. While the SSC output seems to be about 3.3volt-ish
I won't post here, but this is an album showing some traces:
'perfect' square wave reference, SSC output, 1, 2, 3, 4, and 5 foot intervals along the data line (colors begin to fail at 3 ft), 5 foot interval with 97 ohms to dampen the ringing (colors OK), the data out of the first node, and finally, the node-to-node data at 8 feet.
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LoginSo in summary:
The data is cleaned and amplified by the node. If the first node does a good job, then all is well.
The node-to-node data is stronger, cleaner and less susceptible to ringing. 8 foot transmission seems to be no problem.