Wiring clarification

[bmarvel]

I'm in the process of removing the six pack and vacuum system from my RV-8A and replacing it with a D-100 and HS-34. The avionics are an SL-30 and a GX-65, although I realize the GX-65 is apparently not yet compatible. No worries, I'll wait.

I am in the process of wiring everything up to the D-100 and remote compass/OAT and all is working fine. Am awaiting the HS-34 shipment. I'll address HS-34 questions in a moment but have these two questions right now about just installing the D-100 without the HS-34:

1. The install instructions specify that pin 22 of the D-100 is used for both uploading software from a PC and receiving serial data from an SL-30. Do you have to physically break the connection between the SL-30 and pin 22 to upload software or can you just turn the SL-30 off? In other words, can't the SL-30 and a PC both be connected to pin 22 all the time as long as the SL-30 is switched off when the PC is uploading software?

2. Regarding serial ports, my understanding (minimal) is that a transmit port of one device is connected to a receive port of another device. If that is correct, I don't understand the diagram on page 2-2 of the EFIS-D100 Installation Guide dated July 7, 2007. As an example, it shows pin 2 of the PC as serial 1 tx and it is connected to pin 10 of the D-100 which is also called serial 1 tx. Ditto with receive. Pin 3 of the PC is called serial 1 rx and it is connected to pin 22 of the D-100 which is also called serial 1 rx. On the following page the D-100 pins (10 and 22) appear to be properly described as I understand how they are supposed to work. Is there a typo on the PC plug nomenclature for pins 2 and 3 on page 2-2?

As to the HS-34:

1. My SL-30 and GX-65 are wired to an MD-200 ILS head through a switching relay. The SL-30 is set to RESOLVER. I do not intend to change any of that but to simply use the SL-30 and GX-65 serial ports to send nav information to the D-100 HSI. Question: For that configuration it appears that I will not need the HS-34 lower plug at all. Is that correct?

2. The HS-34 lower plug refers to ARINC 429 data. I have not heard of this relative to the SL-30 and the GX-65. Is ARINC 429 involved with these two radios?

3. Back to pin 22 on the D-100. Serial input data to pin 22 is required for the HSI nav display when the HS-34 is not used. However, when the HS-34 is used, it appears that there is no output from the HS-34 to pin 22 of the D-100. Since I intend to have both SL-30 and GX-65 serial data sent to the HS-34 and then on to the D-100 for display, how does it get there? Is that what the DSAB does?

All for now, but I will have more!!

 

[dynonsupport]

1) It would vary from device to device, depending on how "off" that device really is when powered off. We haven't done any testing on our end with different radios or GPSes connected, so we couldn't really advise. The bottom line is that if something interferes with the serial connection while you're updating, you'll run into problems. We recommend that you not have any other devices physically connected, period, when updating our products.

2) Your premise is right, but think of the 9 pin serial connector as an extension cable of the pins in the unit themselves, not the device they're connected to.

HS34

1) Theoretically true, provided the serial ports can output simultaneously with the analog connections.

2) Neither of those uses ARINC. The SL-30 provides full data over a serial connection, and while the GX-65 can provide basic CDI data over serial, the higher-fidelity CDI signal that you'd want to use in an IFR environment comes out over the analog lines exclusively. Note that you can only hook up the analog resolver connections to one nav head at a time.

3) The HS34 connects to other Dynon products via DSAB; all o GPSes and other Nav radios then connect exclusively to the HS34.

 

[bmarvel]

Thanks for that information.  It clarifies several vague items in my installation.

Here's a follow up regarding the PC input required for software updates:

Without the HS-34, the PC connects to D-100 pins 9, 10 and 22.  I can make that connection now and upload the latest software.  

However, according to what you have published, when I install the HS-34 the PC will then connect to the HS-34 upper D25 pin 1 (serial 1 rx) and upper D25 pin 14 (serial 1 tx) but there is no pin specified as a serial ground.  Is a serial ground something special which needs its own pin or can I just use pin 17 on the upper D25 (Ground)?  Or must I use the D-100 serial ground pin (9)?    

 

[dynonsupport]

Any aircraft ground would work fine. You could splice into the main HS34 ground on pin 17 on the upper male DB25 connector. Or use a spare ground line from an EFIS or EMS. All grounds are basically electrically identical.

 

[bmarvel]

While waiting for the HS-34 to go in place beside my D-100 I am sketching out how I will tie everything together. Again, this if for an SL-30 and GX-65, both of which have been operating fine in my panel and which "talk" to each other via existing serial data lines. In looking at the actual wiring between these two and the HS-34 it appears that only two wires will be needed from the two radios and that they will each connect to two different pins on the HS-34. This may be OK but seems strange and I'm trying to determine if that is correct.

To keep this "simple," please draw boxes for the SL-30, the GX-65 and the HS-34 with the following pins and connections:

SL-30 pin 4(rx) connects to GX-65 pin 5(tx)

SL-30 pin 5(tx) connects to GX-65 pin 4(rx)

Using the pin diagram you have provided on this site for the HS-34, I have assigned the SL-30 to HS-34 pins 1(rx) and 14(tx) (serial 1) and the GX-65 to HS-34 pins 2(rx) and 15(tx) (serial 2).

Here's my dilemma.

If I wire SL-30 pin 5 (tx) to HS-34 pin 1 (rx), it will also include GX-65 pin 4(rx) because that one is hard wired to SL-30 pin 5. However, HS-34 pin 15 (tx) also must connect to GX-65 pin 4(rx) which is connected to SL-30 pin 5 (tx), the same as shown in the prior sentence.

(Again, please diagram this to keep from going nuts!)

The same holds true for the other half of the serial wiring connecting these three components together.

Is it thus correct that this one wire connecting SL-30 pin 5 and GX-65 pin 4 will branch out and connect to HS-34 pins 1 and 15? It looks to me like that is what will be required but I wanted to make sure.

 

[dynonsupport]

We won't be able to draw you a custom diagram, but here are some answers:

First off - a ground rule. You can't ever have more than one transmitter on a single line. Any proposed wiring that violates that rule will not work.

Your particular configuration is tricky. Ultimately, you're going to need make a tradeoff.

If you leave the SL30 and GX65 connected to each other (presumably you have them connected so that the SL30 can receive frequencies from the GPS), you'd split only the transmit lines from each of those devices and fork their output to the HS34's serial inputs. This allows almost full-functionality: we only use the receive data from the GX65 in the first place, and the SL30 will output full information over serial. The limitation here is that the HS34's course knob will not spin the course when the SL30 is active (it does not have an effect on the GX65 anyway since its course is set by the GPS course). In this case, you'd set SL30 course using the SL30's knob, and its course changes would be reflected on the Dynon HSI page.

Alternatively, if you sever the connection between the SL30 and the GX65, can you connect both units transmit and receive lines to the HS34's serial inputs, and then the HS34's course knob would tune the OBS on the SL30.

 

[bmarvel]

Thanks for the quick reply.  I wasn't expectiing a wiring diagram but only suggesting you convert my text to a graphical depiction to help you understand my question.

I definitely need to keep the GX and the SL talking to each other via the serial lines between them.  Yes, frequencies go back and forth but also the GX provides DME data to the SL when a nav station is tuned in.

Given that need, I understand that I will be branching SL-30 pin 5 (tx) to HS-34 pin 1 (serial 1 rx) and branching GX-65 pin 5 (tx) to HS-34 pin 2 (serial 2 rx).  I will have no connections at all on HS-34 tx pins 14 and 15.

Also, I currently have the SL-30 wired in resolver mode to an MD-200 and plan to keep it.  I now tune in nav courses with the knob on the MD, not with the knob on the SL-30.  I assume that when I wire in the HS-34 as indicated above that when I tune a nav course with the MD-200 knob, that course will be displayed both on the MD-200 and on the D-100 HSI.

 

[dynonsupport]

You nailed it.

 

[bmarvel]

Well, I thought I had nailed it also, but maybe not...

Got the HS-34 a couple of days ago and tried to upload 4.0 into it and the D-100 today. Before I got the HS-34 I had my PC wired directly to the D-100 pins 9,10 and 22 per the install manual. In that configuration I had no problem loading 3.0 into the D-100.

However, when I received the HS-34 I removed the PC connections to pins 9, 10 and 22 on the D-100 and put them instead on HS-34 pins 1, 14 and 17, per the HS-34 pin diagram you published. When I selected the D-100 on the 4.0 software, it said that it detected the HS-34 so I then selected the HS-34 on the software, thinking that the system is smart enough to see the D-100 and the HS-34 and load the proper software to both units. Evidently not.

After doing all of the calibrations I went to the DSAB setup instructions but could not find the DSAB menu. It just wasn't there. Then I checked the software version on the D-100 and saw 3.0 and not 4.0. Apparently this means that the software has to be uploaded to each box individually, which in turn requires a PC connection to each box and two runs of the upload to get it all installed in the appropriate places.

If this is the case, please let everyone know as there is nothing I found in the install manual that clarifies this.

 

[dynonsupport]

Each unit does need to be updated individually using their own serial ports - Firmware updates are not pushed across devices by DSAB.. Also, each device should have its own 9 pin connector hooked up. You want a one to one pairing between each device and its 9 pin plug - do not use a single 9 pin plug and split the wires to multiple devices.

 

[bmarvel]

Alright, I've installed the second 9 pin dsub and successfully loaded version 4.0 in both the HS-34 and the SL-30. Most everything seems to be working but I cannot get any bearing pointers to display on the HSI, either from the SL-30 primary and backup freqs or from the GX-65. As I reported on the general forum, the GX-65 works fine (aside from this BTW problem that I just discovered).

When I press bearing source with the SL selected and course info displayed on the HSI, the colored bar jumps from the primary source line to the secondary source line as it should but they are blank and the bearing lines do not appear on the HSI. No distance or groundspeed information is shown either but both of these display properly on the SL. I don't see anything in the install or user manual that explains how to get these pointers up and running.

By any chance is this a problem caused by my MD-200 and the SL set to resolver mode? If so, why would it affect the GS-65 bearing pointer also? I have no problem slewing the nav course selector on the HSI with the MD-200 course selector knob when the HS-34 is set to nav and the SL is driving the show. It appears to be working almost perfectly in just about every other respect.

I'd like to get the bearing pointers. Any suggestions??

 

[dynonsupport]

When the bearing pointer line is highlighted, you turn the value knob to choose the source. Bearing source toggles the cursor, but value changes it.

Press the bearing source button, then turn the value knob. It should work.

 

[bmarvel]

And so it does! I had not read far enough in the pilot's user guide before asking the question. But I do have another related to it.

Both the NAV bearing and the SBY bearing point to the VOR tuned into the active frequency even though the standby frequency is tuned to a different nearby VOR that is received clearly. The NAV bearing points correctly as does the GPS bearing but the SBY bearing just follows the primary NAV bearing pointer.

There's probably something I'm doing to get this result but I can't determine what it is. Any thoughts?

 

[dynonsupport]

We haven't seen that before. It's possible you've uncovered a bug. We're going to investigate. If you are computer-savvy and know how to capture the serial data stream off of your SL30 with a computer, we'd love to have a data sample from your unit (email it to support@dynonavionics.com). If you don't know how, but are adventurous and pretty computer literate, give us a call at 425-402-0433 (ask for tech support) for some help on how to capture that data.

 

[bmarvel]

I don't know how to do any of that but at one time I didn't know how to build an airplane either.....

Will call you guys and find out what I have to do to get you the info.