FDS SYS board connections

[Sean]

I'm about to order a SYS board for my overhead and was wondering how you guys have tackled the issue of connecting your switches and LED's to the board?

Taking a typical 9 way input strip (8+1 ground), how are you connecting the cable from the switch to the cable from the board connector? A simple connector block?

And are you stuffing all 8 grounds into 1 block? Or wiring 1 ground to 8 switches?

By my reckoning, thats a lot of connectors for the overhead. I was thinking of making an intermediate connection board to try and keep things neat, or am I barking up the wrong tree here?

[vidarf]

Check this out:

http://fagerjord.org/index.php/737-cockpit-project/34-cockpit-related/55-interfacing?start=1

If you have an overhead without integrated backlighting, you should follow my example. LOT of work, but you'll get a reliable system out of it.

Basically, I decided the different groups of switches and annunciators:

Switches: connect the ground wire (common) to the first switch, then run a wire to the next switch, then to the next... Connect ONE wire to each switch for the input function. Remember that you cannot wire all the grounds together!!! 1 ground per group of 8 inputs.
Also remember that you only need to use one input on a 2-way switch (on-off style), or 2 inputs for a 3-way switch.

Practical example: The APU switch. It has 3 states: off, on and start. This is how you can wire that one up:

input 1: OFF
input 2: START

Use a ON-OFF-(ON) switch. The (on) means a momentary state; the switch jumps back to the OFF position when you let it go.

In InterfaceIT, you set the switch up like this:
Input 1 ACTIVE: "set the apu to off"
Input 1 INACTIVE: "set the apu to on"
Input 2 ACTIVE: "set the apu to start"
Input 2 INACTIVE: "set the apu to on"

This means that when neither of inputs 1 or 2 are active, the switch has to be at the "ON" position.

This is where people might be confused. So ignore what the physical switch actually do. If it is ON, it could be OFF!

As for outputs:

Reserve 2 outputs on EVERY OUTPUT GROUP for dual state, blue annunciators! This gives you 6 outputs per group for all the other annunciators.

One common ground to 6 annunciators, one wire to each per output.

As for the dual brightness ones, I suggest you make a modified board with resistors, as I show on my website. I'm talking about this one:


In stead, run two lines AND the ground to that card:

--(GND) -----------------------------ANNUN-
--(BRIGHT)----DIODE--------------CIATOR
--(DIM)--RESISTOR--DIODE---/

The bright and dim "lines" meet after the diodes, and you end up with 2 wires that you should connect to the annunciator. It makes it MUCH easier than what I did.

Just ask if you did not understand that one. I'll make a better connection diagram. Hard for me to explain.

More questions? Fire away!

[Sean]

Thanks for the tips Vidar, I will certainly bear them in mind when I come to wire up the overhead.

But my original question related to connecting the pre-wired harness that comes with the SYS board to the wire coming from the switch. Of course I am assuming that the wire is not connected directly to the switch. I'd assumed they wouldn't be long enough, perhaps I'm mistaken?

I'd assumed you would have to connect a wire to the switch and then connect this wire to the wire coming from the SYS board. Meaning a connector somewhere in the circuit. Given the amount of wires in a typical overhead, that equals a lot of connectors.

[vidarf]

YOU DON'T SAY!!!! Yup, you will need to extend E_V_E_R_Y single wire! Big job. But definitely a better idea to do that, than to incorporate some other arrangement.

Here's how I did it:

1. Get a "helping hand" tool. The one with 2 claws and a magnifying glass. It's going to be your new best friend!
2. Get a wire stripper. I HIGHLY recommend the one I'm using (check my website). The "automatic" type does not work for long...
3. Get solid-core wires. Easy to bend in a desired shape, and it stays that way. People will argue that the core breaks easy. Not if you are a little bit careful; don't bend it back and forth or it'll break, just like a paper clip.
4. Get a buttload of zip-ties. I don't use that word to be (too) funny!
5. Get shrink-tubing that will shrink down to 1mm when heated.
6. If you don't have one, get a kitchen torch. Great for making Panna Cotta too... If you light it, you can adjust the flame to the point where it is neither a flame nor a torch. Perfect for shrink-tubing.

Extending a wire: Cut a foot of wire (depending on where you mount the SYS cards), strip off the insulation about .5 cm. Do the same with the FDS wire. Cut a 1.5cm piece of shrink-tube. Fasten the FDS wire in the helping hand and slide the shrink-tube onto it, away from the exposed wire core. Fasten the other wire (solid core) in the opposite claw of the helping hand so that the two wires meet. Twist them together with two fingers, then solder them together.
Slide the shrink-tube over the joint and use the torch to shrink it down. Be careful, or you'll burn the tube! You need to apply heat all around. Move the flame back and forth. Remove the wire from the helping hand, and twist the shrink tube a little (careful, it's still hot!).

Repeat a gazillon times!

I recommend that you make 5-6 of the extended wire bundles to start with. Plug the connector into the SYS card and route a wire to its destination. Solder in place. Repeat. When you're finished, zip-tie that wire bundle along its path.
When you're finished with all the wires, you can zip-tie the bundles together and secure them to zip tie plates (has double-sided tape on one side and a fastening loop on the other side).

And here's the genius part about the SYS cards:
You do not need to pay ANY attention to the order of the in- or outputs! It does not matter if the left engine generator switch is connected to input 3 and 8 instead of 1 and 2! You don't need to remember anything at all!
The same goes for the outputs, except output 7 and 8 in ALL the groups. Those are the ONLY ones you need to pay attention to. Of course you will end up with a lot of 7's and 8's that won't be connected to anything. Just chop those wires off the connector, but do that when EVERYTHING is connected, tested and working. Easy to forget one...

In InterfaceIT, you select "identify input" then flip a switch. The input that's being activated, will automagically be selected. You can then assign the function.
For the outputs, you need to do it a little bit different. Choose an output and select "inverted" in the menu. The annunciator will then light up and you can assign the function to it.
NB! Write down which outputs aren't connected to anything. Will save you a lot of time.


Yup, it is a lot of work. It will take you a couple of days - or a lot of evenings. I recommend something tasty in the cup (stay sober though - your'e literally working with flames and molted metal!) and some good music.

If your overhead comes from FlyEngravity (like mine), you need to keep the wires away from the cutouts for the backlighting. It's easy to do with solid-core wires.

Here's how the back of my overhead looks. The AFT overhead is not connected yet:





Detail image of some switches and annunciators:



Here's the URL for the page on my website with those images:

http://fagerjord.org/index.php/737-cockpit-project/34-cockpit-related/55-interfacing?start=1




PS: I recommend that you buy one color for the switches and one color for the outputs. Also get two different colors for the common grounds. I only had white and black. It does not really matter, but it would be a better way to do it.

I will also recommend that you write the first in/output on the connector. If you need to remove the SYS card, it will be easier to reconnect everything without loosing the setup. So for the first connector (connected to input 1-8) you write "1". The next, you write "9" since the first output in that group will be number 9 overall.

[vidarf]

I forgot to mention WHY you should do 4-5 looms at a time. When you're connecting a wire to a switch (or output), save the cutoff. You don't need 3 feet of wire everywhere. Re-use the cutoffs. It won't take long before you get an idea for the lengths you need.

In the first image of the latest post, you can spot an extension point at the upper left edge of the image. A thick, black part of a white wire just above a zip-tie.


PS: I might go overboard on the explanation here, but then the info is out for the future.

[Sean]

Overboard? You? Noooo! 

Good advice, thanks for sharing that, but I'd already made my mind up that I wouldn't be extending the wires (if they needed extending, and now I know they do) that particular way. I had oririginally thought about making a bespoke board with enough connection points on it to terminate in incoming and outgoing cable through that, but that's a lot of terminations.

What I'm thinking of doing now is getting some of the steel pins that go inside the 10 way SYS connector and making up new looms with tails long enough to go direct to each switch/LED.

What I'm still unsure about is how to tackle the grounds. I'm not keen on taking a common ground to 8 switches or LED's. What I might do is create a separate terminal block just for the grounds.

I'll order up the board and see what happens!

I'll stick with the CPFlight MIP board for now. Put that money towards the elec panel instead.

Cheers Vidar.

Sean

[jackpilot]

Sean

Syscards are a breeze to use.

You would have far too many connectors, soldering the wires end to the connector wires and adding a heatshrink over is the way to go.
To avoid lengthening these wires there is a simple (slightly costly) way.
Buy the crimping tool which is used to connect the wires to the terminal.
FDS can supply bare terminals.
You just have to run each wire, full length from the switch/led to the Syscard location
Crimping 9 wires takes max  30 seconds vs 9 solder/heatshrink steps.
I did my MIP the hard way , I would nt even touch the overhead without the crimping tool.
Ask Mau, he will agree.
(actually I went a step further and ordered the OVH Plug and Play . Lazy body :yes, sorry about it: NO)

[Sean]

Hi Jack

Yes, the method you describe was the one I was trying to describe above. I don't fancy the splicing method. It wouldn't fit in with my OCD at all! 

[fdspcos]

Guys,
Keep in mind that you can "loop" your grounds for each connector at the hardware side. Our FDS-AN1 units are three wire with that third wire being a loop for the next an1 to be connected. You can easily do this with switches.....
Example, you have eight toggles to wire. Each toggle gets its own wire from the connector. The "common" wire runs to the first toggle, that common is then looped from the first toggle over to the second and all the way to the eighth toggle. You don't need to run individual commons for every device. You would have a mess, an unnecessary mess.
Having the actual tool is ideal but they are expensive, about $300. We use them all day long as you can imagine but they are gold around here. I wish I could rent them out but the cost to ship them all over the globe is problematic.
Peter

[XOrionFE]

This is how I did mine (like Peter describes....daisy chaining the grounds).  There is also a smaller t handle type manual crimping tool that costs only abou $50 which is what I used to do my whole overhead.

Scott

[vidarf]

Thought I was being clear, but apparently there's some board left...

In my setup, the common ground for a group of 8 switches or annunciators are looped. From the sys card to the first switch, from the first switch to the next. It is barely visible in the last image I posted (that's the fuel pump switches). The common comes in from the bottom left, moves through the left and right pumps, up to the center pumps, to the cross feed and over to the left to another switch.
Easy to spot that on the annunciators too. On that group (6 amber annunciators), the last output is used for the cross feed (i'm using output 7 and 8 for the blue, dual state annunciators as mentioned earlier).

That's how I did it, and I would STRONGLY recommend people following my example unless they get a molex tool, terminals and start making their own wire looms. Forget connectors and spreader boards. Does not make anything easier, adds cost and is - in my absolutely not humble opinion - a waste of time, effort and money.

OR - you could chicken out as Jack did. What a whimp!

[Joe Lavery]

Vidarf,

It looks as if we took the same route, I've attached some images including my own Yurika moment.
As Peter mentioned the negatives (or ground) for each set can be connected in series.

Cheers
Joe.

[vidarf]

yup, that's exactly how I did it. Even the small PCB's for the annunciators...

[Flying_Fox]

Speaking about FDS card wiring...

I just started my MIP wiring and got confused by FDS manual (http://www.flightdecksolutions.com/pcupload/FDS-SYS-MAN-V5.pdf).

I have:
Output connectors - 8 white wires + 1 black common wire
Input connectors - 8 PURPLE wires + 1 common BLUE wire

According to page 14,  the rotary selector is connected the following way:

Signal PURPLE wire goes to central pin and all 4 outside pins go to BLUE wire  so, according to existing wire colors, that makes them all connected to the common wire. 

While my understanding is that it has to be exactly the opposite. Outside pins have to be connected to the PURPLE signal wires and central to the BLUE common wire.

In addition the manual refers to RED signal and black common wire for the outputs, which is not the case for the FDS SYS card I received. However, I've seen pictures of FDS cards with Red/black output wiring.

What am I missing? Is the manual outdated?

[Nat Crea]

While my understanding is that it has to be exactly the opposite. Outside pins have to be connected to the PURPLE signal wires and central to the BLUE common wire.

Sorry...but yes, FDS wiring standard has evolved over the years, and the manual
has a few old examples in there which may confuse.

Your logic is correct, the single blue and black is common/ground now.

Cheers,

Nat

[Joe Lavery]

That's how I connected mine, they were 8 purple and a single blue. I think the manual is wrong. If you look back at my contribution to this thread you'll see the images I posted shows that configuration.

Joe.

[Flying_Fox]

Thank you Nat and Joe for the confirmation!

Yes, I've seen the pictures here - that's why I posted in this thread. So, now I am doing the wiring your way.

Nick