Network Cable connections / decisions

[rgcrothers]

I am about to route the network cable from the display back through the airframe to the ADHARS unit on my RV7A. The ADHARS unit will mount where most people have put them, up high and well behind the baggage area bulkhead. Mine is not a slider.. but a tip up.

It seams to make good sense to use a splitter at the ADHARS to branch off to connect to the elevator auto pilot servo as they are in fairly close proximity, using separate power and ground wiring of course, and disconnect also.

The routing of the network cable goes down the passenger side vertical support area above the spar on down to the floor area before heading rearward. My choice is to either cut into the harness at this point, put in a splitter for a branch out to the roll servo, or possibly make a separate run from the servo all the way back to the display for the roll servo. One consideration is that a separate run would eliminate the db9 connections down low and out of sight in the on the airframe. I have some concern about moisture contamination on those connections so I am leaning toward making the seperate run back to the display.

Looking for feedback on the logic here from those more familiar with the best practices with regards to the network wiring.

Randall

 

[jakej]

Randall

You could do it either/any way however make sure that the servo Pwr & Gnd wires are 20awg and the power comes from a separate circuit breaker or fuse - don't use the Network power wires.
I've never found moisture contamination to be an issue however you could 'wrap' the connections with something like self amalgamating tape for example

Jake J

 

[rgcrothers]

Thanks jakej,

I managed to avoid placing connectors down low in the airframe. Doing otherwise would have meant having 3 separate 9 pin Dsub connectors down low in the airframe and under the floor where they would only get looked at during annual and other inspections. I feel more confident in the system having those connections up behind the panel or other areas where they can easily be looked at, and preferrably up higher away from potential moisture contanination.

So I ran a separate servo network harness back to the dispaly from the wing.

I called in to support with a question to verify it is OK to have a servo between the display and the ADHARS unit. The answer is yes it is OK, but with a warning that the servo network wiring does not contain all 9 wires that are needed by the ADHARS. Extending beyond the servo with the servo wires will not work without adding a few wires.., all 9 are needed at the ADHARS.

I managed to find enough wire to make the run all the way up to the ADHARS and will split off there to run down the the pitch servo.

All is good!

Randall RV7A

 

[mmarien]

I added my servos a year after I installed the Skyview. Rather than reroute I just cut the four wires in the network cable to the ADAHRS and used a 8 connector terminal strip to splice in the servo network cables and add the power and CWS button for the servos. I crimped both ends of the cut network wires to the same terminal connector and connected that to one side of the strip. On the other side I connected the servo wiring but used separate connects for each servo and just doubled up the connectors on the screw down.

Benefits are that the wires are screwed down to the terminal strip rather than having DSUB connectors and each servo is removable. Network cable is continuous to the ADAHRS. It also makes a convenient place to splice in the power and CWS.