PanelDue 4pin connector vs CONN_SD for long distance connection?
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Hi,
I have a bit of a weird use-case, the Duet 2 mainboard is located ~800mm away from the PanelDue.
Out of curiosity, what is the difference between the 4 pin connector vs the 10 pin CONN_SD, and which cable should be used, or both at once?What could be done to increase useable distance away from the mainboard?
I am uneducated in the M575 command, so I am not aware if this could be a possible solution.Extra info:
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Every now and again I do get a 'malformed message' response logged on the screen at these distances, and when the board is at 100% powerusage (432w bed heater, and 40w nozzle heater) the error rate does spike regardless of cable length)
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Sometimes the screen just 'hitches' where it doesn't receive any updates for a couple seconds, then pops an error onto screen starting with M408 but ending with a bunch of random/corrupted characters
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The SD card in the screen is not being used, I am only using the screen for in person control when the webGUI is not available.
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Clone boards are a lot more prone to these malformed messages, but again only when at high power
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To reach 432w on the bed, the 15A fuse was replaced with a 20A fuse
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Duet2 is using RRF 3.4.0, Screen is also updated (Screen is Fysetc 7' based on the V3 design)
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Use the 4-wire connection for the best distance. Use high quality cabling. Route the cable away from any motor or heater cabling. Doing a braid on the 4 wire cable may help prevent it from picking up interference.
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@phaedrux 4wire cable it is!.
Is there anything in the M575 that would be helpful, as I know some stuff got added for RRF 3.4, unsure about if any of these changes would help.
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The default baud rate should be the most stable over long distances.
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@notepad To your initial question: with luck, you can bridge the 800 mm with a proper cabling to the 4 pin connector. The ribbon cable is not specified for those distances.
Now to your "Extras". Looks like you are buying cheap, and no, I don’t talk about "error-prone" clones but about your power supply: if you encounter increased error rates at full power, the voltage is not stable. Finally, to replace the 15A fuse with 20A just to accommodate the needs of your bed heater is insane. Before fiddling around with M575 for baud rates, fix the fundamentals: use a SSR for your bed and provide stable power.
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@infiniteloop The fuse replacement was only to be able to pull 16.5A instead of the standard 15A, as I know the fet that controls the heaterbed power is rated upto18A, and the heater is limited in software to only pull 400w.
So far the voltage from the PSU is stable, as I have been using a benchtop PSU just for testing and bugfixing, though I have a feeling the issue may now be caused by interference from the heater bed wires that run directly next to the screen cables.
My question regarding M575 is mostly regarding the 'S' value, as RRF3.4 unlocks mode 4 and 6 in regards to checksums, but there isn't much information on how the checksum process works for these devices and if it would be a simple fix to go from S1 to S4
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@notepad said in PanelDue 4pin connector vs CONN_SD for long distance connection?:
the heater is limited in software
That's keen! Let me guess: you cap the PWM? If that's true, you put the said FET to a stress test.
the heater bed wires that run directly next to the screen cables
Put them elsewhere.
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@infiniteloop said in PanelDue 4pin connector vs CONN_SD for long distance connection?:
you put the said FET to a stress test.
Yup, nail on the head. Slap a temperature probe onto the FET and repeatedly 100% load cycle it while capturing the data.
By removing the 15A fuse, I'm flying close to the sun, so id rather make sure the parts are capable in the event I push a config update and forget to limit the PWM to the heater.So far the temps are more than manageable, which just shows how good of a design the duet mainboards are.
The middling quality of some of the clones however do leave a lot to be desired, and run a bit hot for my liking.At the end of the day, if it blows while on the bench, its interesting data. If it blows in production, its gonna get messy real fast.
@Phaedrux Any idea if putting M575 to S4 instead of S1 would have any positive effect?
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@notepad said in PanelDue 4pin connector vs CONN_SD for long distance connection?:
I'm flying close to the sun
I wouldn't dare to contradict
But, talking about the PanelDue: first, you must keep its connection distant from strong power signals. Second, you should try to use a separate power supply: increasing error rates at full power indicate unstable conditions of your benchtop PSU.
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@notepad said in PanelDue 4pin connector vs CONN_SD for long distance connection?:
Any idea if putting M575 to S4 instead of S1 would have any positive effect?
Feel free to try S4. I think having crc should be an improvement.
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@phaedrux said in PanelDue 4pin connector vs CONN_SD for long distance connection?:
Feel free to try S4. I think having crc should be an improvement
To use S4 you will need to use the latest beta PanelDueFirmware.
