CAN-bus overload danger
1701 5 2019-2-24
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eggbeater
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I'm using all four CAN-bus accessories from DJI on a Cendence.  Patch antenna, GPS unit, focus wheel and multilink. I just recently added the multilink now the focus wheel does not work unless I take one of the other CAN-bus accessories off line.  Each CAN-bus device works on its own but not all together.  With the GPS unit taken off line the focus wheel is intermittently disconnecting with a flashing blue light.  It would seem to be a power load that the CAN-bus circuit cannot support when all four devices are powered up at the same time.  Has anyone else experienced this?  This CAN-bus circuit is power for the patch antenna amplifiers and I have become unconfortable with a loss of that power supply due to an overload and a possible resultant disconnect with the aircraft or reduced distance.  

2019-2-24
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HyperSpectral
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Have you checked the voltage on the power pin referenced to ground when 3 vs 4 devices are connected? You can probably provide a secondary power source and wire only CANH and CANL to some of the devices if it's a power problem and not saturation of the CANBUS
2019-2-25
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eggbeater
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I appreciate your suggestion.  And while I'm familiar with a VOM I gave that up when I migrated to the DJI RTF platforms.  Providing additional power to DJI devices is not an option and It would seem such testing would have been performed by DJI engineering before sales release and a warning, solution or workaround issued as to usage of the devices unless there is a defect in my Cendence hence the question "Has anyone else used these devices all at the same time successfully?".
2019-2-25
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HyperSpectral
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eggbeater Posted at 2-25 10:00
I appreciate your suggestion.  And while I'm familiar with a VOM I gave that up when I migrated to the DJI RTF platforms.  Providing additional power to DJI devices is not an option and It would seem such testing would have been performed by DJI engineering before sales release and a warning, solution or workaround issued as to usage of the devices unless there is a defect in my Cendence hence the question "Has anyone else used these devices all at the same time successfully?".

You're right, the premium you paid should include that sort of testing but it doesn't. You bought a DJI product knowing that they do this kind of thing.

I'm not excusing DJI, but sometimes you have to waste your own time to fix a problem before DJI actually does something about it.

It's pretty basic and I can walk you through it, just let me know. Setting a DMM to dcv is the hardest part
2019-2-25
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eggbeater
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The response from DJI is deafening.  Do they still monitor this forum?
2019-2-25
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Drone Tech Aerial
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Flight distance : 2951900 ft
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Having a similar issue. Multilink and focus wheel 2 will not work at the same time. Exclusively both units work on their own. Put them together focus wheel light flashes and sometimes the wheel works ver intermittently sometimes not at all. Has this been resolved? I am using the stock I2 controller NOT the cendence.
2019-6-13
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