Network detect fails to detect one servo

cbretana

Member
Joined
Jul 10, 2019
Messages
274
Installing pitch and roll servos. When i connect pitch servo to hub and roll servo to display, network only finds roll servo. Configuration and test of roll servo is then normal. Ailerons deflect properly during test.

So I then switch, and connect pitch servo to display and roll servo to hub, and network only recognizes pitch servo! Configuration and test on pitch servo proceeds normaly. Elevator moves properly.

Does this evidence indicate that port on hub is bad? Should I splice together data in and data out wires from both servos to one D9F connector and hook it to back of display?
 

jakej

Well-Known Member
Joined
Oct 10, 2007
Messages
2,079
Location
Adelaide, Australia
I nearly always splice both servos into 1 x dsub connector to a hub, reduces the need for a second hub.
you could try another port on the hub too.
 

cbretana

Member
Joined
Jul 10, 2019
Messages
274
Yes, splicing them together and only using only one db9/port should work. That's my next plan. I am out of ports on the hub otherwise.
Someone at Dynon told me you couldn't do that with servos, but as i undersrand the network, that does not make sense. Perhaps I misunderstood what he told me.
 

jakej

Well-Known Member
Joined
Oct 10, 2007
Messages
2,079
Location
Adelaide, Australia
Most likely a misunderstanding- a network is a network is a network, we’re talking about 2 x pairs of wired here (4 in total). As you most likely are aware the servo power & grounds are 20 gauge & the power has to have an independent circuit breaker system from the network cable, the only other wire needed is the servo disconnect giving a total of 7 wires ;).
 

cbretana

Member
Joined
Jul 10, 2019
Messages
274
Yes, i spliced the four data lines together into one DB9F connector, plugged that into one port on back of display and it all works.
As an aside, after running mutiple tests (of network configuration, detect function), with separate servo connectors plugged into various ports on hub, and into the two ports on display, in various combinations, any time I had a servo plugged into the hub, (any one of the five ports on hub), the system failed to detect that servo. When connected to the back of the display, the Servo, (or servos), connected to the display were succesfully detected.
What is curious is that all the other Skyview components function normally when plugged into any of the hub ports.
Dynon is sending me a new hub on RMA. Although everything is now working, I am curious to see if replacing the hub corrects the issue.
 

XPRSAV8R

Member
Joined
Jul 9, 2019
Messages
80
Location
Houston Area
Sounds like your problem only occurs when you have multiple servos connected/spliced together. Perhaps get a multimeter and check for signal strength. Maybe your runs are too long and you're losing power/signal. By the way, mine is spliced and it works. Also, I did have a similar issue where the SkyView network failed to detect a servo. I swapped ports, I swapped wires, I measured signal, etc, etc. It turned out to be a defective servo.
 

cbretana

Member
Joined
Jul 10, 2019
Messages
274
Sounds like your problem only occurs when you have multiple servos connected/spliced together. Perhaps get a multimeter and check for signal strength. Maybe your runs are too long and you're losing power/signal. By the way, mine is spliced and it works. Also, I did have a similar issue where the SkyView network failed to detect a servo. I swapped ports, I swapped wires, I measured signal, etc, etc. It turned out to be a defective servo.

No, actually, the problem went away when I spliced the wires from both servos, AS LONG AS I CONNECTED THE SINGLE DB-9F PLUG INTO ONE OF THE HDX DISPLAY PORTS. If I connect it to the hub, neither servo is detected/recognized.

And I considered the hypothesis that it was a bad servo, but, (before I spliced them together), if I connect one to the hub, and one to the back of the HDX display, whichever one is connected to the Display port is detected/recognized, and whichever one is connected to the hub is not.

And I now also know it is not the hub, I had Dynon RMA me a new hub, and repeated all of these tests with the new hub, and the same symptoms/aberrant behavior is occurring with the new hub as well.
 

XPRSAV8R

Member
Joined
Jul 9, 2019
Messages
80
Location
Houston Area
That’s truly bizarre. The servos have 2 pairs for communications. One pair is redundant for the other pair. It’s unusual that the servo would fail detection like that. Perhaps disconnect one pair and see what happens. If it detects, it’ll warn you about the other missing pair.
 

cbretana

Member
Joined
Jul 10, 2019
Messages
274
Did that... When only one was connected, (no matter which one it was), it would be detected if it was hooked up to the back of the HDX display, and not detected when it was hooked up to the hub. And the two pairs are there because (as in all networks), it needs one pair for sending data packets, and one pair for receiving data packets. They are not interchangeable and neither pair is redundant.

But I agree whole-heartedly that this behavior is bizarre. I am pursuing this primarily because I am intensely curious as to what the explanation will turn out to be...
 

DBRV10

Active Member
Joined
Jun 15, 2008
Messages
925
Location
Brisbane, Qld. Australia
Correction for you......There are two networks for redundancy and if one fails it will still work and you get a fault telling you which pair has the fault. The old D10/100 series only ran a single two wire network. SV has two x two wire networks.

I suspect you could have a power supply problem.
 

cbretana

Member
Joined
Jul 10, 2019
Messages
274
I see the wiring diagram refers to these pairs as Data B1 and Data B2
I assumed they were for data in and data out, respectively, as they are in an Ethernet network...
Thanks..
 

XPRSAV8R

Member
Joined
Jul 9, 2019
Messages
80
Location
Houston Area
Data in/out (typically indicated as TX/RX) consists of a pair of twisted wires. B1 is a twisted pair and B2 is a twisted pair, and provide redundancy for one another as previously mentioned. Since you’ve isolated wiring and confirmed functionality/detection when an individual servo is connected whether directly to a SkyView display or to a network hub, you may want to check your electrical wiring from servo harness to the circuit breaker and circuit breaker to the power bus when spliced. You may have a voltage drop or insufficient current. A multimeter can’t help you.
 
Last edited:

kellym

I love flying!
Joined
Sep 29, 2013
Messages
272
I see the wiring diagram refers to these pairs as Data B1 and Data B2
I assumed they were for data in and data out, respectively, as they are in an Ethernet network...
Thanks..
Just a dumb question. Do you have a network cable from hub to the back of the panel? Yeah, I know, dumb question.
 

cbretana

Member
Joined
Jul 10, 2019
Messages
274
Yes, from the hub into one of the two network ports on the display. I needed it because I have AHARS, a separate Magnetometer (SV-MAG-236), SV-Com Panel (SV-COM-PANEL), and EMS (SV-EMS-220) so I needed a hub...
The AHARS and the SV-COM-PANEL use two of the ports on the hub, and the SV-MAG-236 and the SV-EMS-220 are spliced together and use a third port. That left me with two open ports. One of course was needed to connect the hub to the display. So when I initially began installing the two Servos, it was natural to connect one servo to the open port on the hub, and the other to the open port on the back of the display. When I did that only the servo connected to the display port was detected/recognized. That's how this started.
Remember, all those other components were connected through the hub, and the network connector between the hub and the back of the HDX display, and they all were detected and functioned properly, so all the ports, wiring and whatever else was involved must have been (and still is), functioning properly as well.
 

cbretana

Member
Joined
Jul 10, 2019
Messages
274
Six months later. I am now having another issue. All of the A/P functions are working as advertised, but whenever the A/P is on I get continuous audible "Caution" messages over the intercom. They only last a split second, so I can never hit the message button fast enough to see the pop up window to see the details. It is extremely annoying, and I cannot turn them off.
Posted this on this thread because I wonder if this is related to other issue.
 

DBRV10

Active Member
Joined
Jun 15, 2008
Messages
925
Location
Brisbane, Qld. Australia
I cant remember now, but in the downloadable data logs there is a fault logged, and even if it is one that comes and goes it will be logged. I say this because I cant recall if this applied to the D100 series or just the SV. But if it does, go take a look.
 

cbretana

Member
Joined
Jul 10, 2019
Messages
274
I downloaded the Data logs, and one of the files is Alerts... a portion of which looks like this:
6502.44,2,9,2020-07-12 14:55:23,+37.09436,-110.59238,11087,133.1,288.6,-10.1,14:55:41,AUDIO,PLAY,SYS_CAUTION,
6502.50,2,9,2020-07-12 14:55:24,+37.09441,-110.59257,11087,133.0,288.5,-10.1,14:55:41,TEXT,HIDE,AP DISCONNECT BROKEN,
6503.00,2,9,2020-07-12 14:55:24,+37.09450,-110.59293,11088,132.9,288.4,-10.1,14:55:41,TEXT,SHOW,alertAP DISCONNECT BRO,
6503.00,2,9,2020-07-12 14:55:24,+37.09450,-110.59293,11088,132.9,288.4,-10.1,14:55:41,AUDIO,PLAY,SYS_CAUTION,
6503.06,2,9,2020-07-12 14:55:24,+37.09450,-110.59293,11088,132.9,288.4,-10.1,14:55:41,TEXT,HIDE,AP DISCONNECT BROKEN,
6503.81,2,9,2020-07-12 14:55:25,+37.09465,-110.59348,11089,132.8,288.2,-10.1,14:55:42,TEXT,SHOW,alertAP DISCONNECT BRO,
6503.81,2,9,2020-07-12 14:55:25,+37.09465,-110.59348,11089,132.8,288.2,-10.1,14:55:42,AUDIO,PLAY,SYS_CAUTION,
6503.88,2,9,2020-07-12 14:55:25,+37.09465,-110.59348,11089,132.8,288.2,-10.1,14:55:42,TEXT,HIDE,AP DISCONNECT BROKEN,
6505.31,2,9,2020-07-12 14:55:26,+37.09493,-110.59457,11090,132.6,288.0,-10.1,14:55:44,TEXT,SHOW,alertAP DISCONNECT BRO,
6505.31,2,9,2020-07-12 14:55:26,+37.09493,-110.59457,11090,132.6,288.0,-10.1,14:55:44,AUDIO,PLAY,SYS_CAUTION,
6505.31,2,9,2020-07-12 14:55:26,+37.09493,-110.59457,11090,132.6,288.0,-10.1,14:55:44,AUDIO,PLAY,SYS_CAUTION,
6505.38,2,9,2020-07-12 14:55:26,+37.09493,-110.59457,11090,132.6,288.0,-10.1,14:55:44,TEXT,HIDE,AP DISCONNECT BROKEN,
6505.88,2,9,2020-07-12 14:55:27,+37.09503,-110.59494,11091,132.6,287.8,-10.1,14:55:44,TEXT,SHOW,alertAP DISCONNECT BRO,
6505.88,2,9,2020-07-12 14:55:27,+37.09503,-110.59494,11091,132.6,287.8,-10.1,14:55:44,AUDIO,PLAY,SYS_CAUTION,
6505.94,2,9,2020-07-12 14:55:27,+37.09503,-110.59494,11091,132.6,287.8,-10.1,14:55:44,TEXT,HIDE,AP DISCONNECT BROKEN,
6506.25,2,9,2020-07-12 14:55:27,+37.09512,-110.59530,11091,132.5,287.8,-10.1,14:55:45,TEXT,ACK,,

So I'm thinking I need to check out the Autopilot Disconnect button for an intermittent short, or break...
 

jnmeade

Active Member
Joined
Oct 9, 2011
Messages
305
Location
Eastern Iowa
Isn't checking the disconnect button part of the configuration? Would it do any harm to re-run the AP configuration and see if that helped the problem?
 

cbretana

Member
Joined
Jul 10, 2019
Messages
274
Good idea, I will. It is interesting that the alert log indicates that this caution alert is happening over and over again, (every few seconds or so), on and off, in spite of the fact that the Autopilot is on and functioning properly. I have a resistor across the momentary switch, as specified in the installation instructions. I wonder if one of the ends of that resistor is broken and intermittently making contact.
 

DBRV10

Active Member
Joined
Jun 15, 2008
Messages
925
Location
Brisbane, Qld. Australia
Good idea, I will. It is interesting that the alert log indicates that this caution alert is happening over and over again, (every few seconds or so), on and off, in spite of the fact that the Autopilot is on and functioning properly. I have a resistor across the momentary switch, as specified in the installation instructions. I wonder if one of the ends of that resistor is broken and intermittently making contact.


There ya go! I think you are well on the way to solving the problem.
 
Top