Installing a EV-100 Cable question

[Don Crowther]

Good Day

I have a 93 Hunter 33.5 that I'm installing a new auto-pilot in. I've mounted the ACU and the Evolution autopilot in the rear closet close to the electrical panel. The P70s (control head) I've mounted in the same location as the old control head which was on the port side coaming.
My question is because of the long cable run from the control head to the ACU the only cable that came with the AP that is long enough is the one with the blue ends.
The P70s has white cable that attaches to it. then I will have to use the blue cable to make the run to the back bone. If i plug into the blue socket will the data get to where it needs to be?
Evolution Cabling Kit

• 1 x SeaTalkng Power Cable (0.4m)
• 1 x SeaTalkng Backbone Cable (5m)
• 1 x SeaTalkng Spur Cable (0.4m)
• 1 x SeaTalkng 5-way Connector Block
• 2 x SeaTalkng T-piece Connector
• 2 x SeaTalkng Terminator

Thanks

 

[BrianQ]

All data that is on the SeaTalk NG network is available to all connected devices. I suggest you download and read the SeaTalkng Reference Manual. It tells you enough of what you need to know about building a STNG network.

 

[jssailem]

Here is the SeatalkNG manual.
Blue is back bone. You want tat to get the data to near the control the other units.

Your blue cable goes into a T-piece. A White cable steps out of the T-piece to your P70 or any other needed connections.

Be sure to use a Blue Terminating plug when you get to the end of the backbone.

 

[Don Crowther]

So the white goes from the p70 to the T and then the blue will go to the 5 way connector block. What happens if you don't use a terminator?

 

[Tally Ho]

It won’t work correctly without a terminator in the T, but… I have successfully put a drop cable in 2 of the T sides (both connected to a device) and it worked fine….so to rephrase, all branches of the T must have something…a device or a terminator.


i just added a Raspberry Pi to my set up, and added a T to add the Pi. My VHF and my Pi take up 2 branches of the T and the 3rd is the backbone cable back to the helm.

For full disclosure, my system is not Raymarine. It is a Garmin CP and a B&G VHF radio, both N2K capable.

Greg

 

[jviss]

If I understand your physical network correctly, and I recall my STNG networking correctly, and that you are only connecting the APU and P70s and nothing else, then the simplest thing to do is to buy a 5m drop cable and use the 5-way connector block as your backbone. So you'd have [1] terminator, [2] power cable, [3] 0.4m drop to APU, [4] 5m drop to P70s, and [5] terminator.

( I thought they used to have a power cable with integrated terminator, which saves a slot, but I'm not sure any more.)

Plan B would be to use the 5m backbone cable to run up to the P70s, and put a T, terminator, and short drop cable up there; connect the other end of the backbone cable to your 5-way, and add the drop for the APU, power cable, and terminator to that.

In any event you need at least another short drop cable.

Make sense? A 5m drop cable is about $55.

BTW, while I no longer have a boat with STNG, I really like their cabling system, except that there's no field termination option.

Update: there's another option, and that's to run the backbone cable up to the P70s and attach a drop cable to the end of it via the Raymarine A06074 In-Line STNG terminator. In this case you would only have one terminator in your 5-way at one end, and the 5m backbone cable in the other end.

 

[Ward H]

So the white goes from the p70 to the T and then the blue will go to the 5 way connector block. What happens if you don't use a terminator?

The Terminator plug has a resister inside. All the RM SeaTalkng references and I believe the NMEA2000 references say there needs to be a Terminator at each end of the back bone.
Why? I don't know. I expect that it has something to do with preventing electrical interference.
I wasn't about to take a chance and not use them when I was installing my EV100 auto pilot. The last thing I wanted was my boat doing a Crazy Ivan when on AP and I was on the fore deck.

 

[jviss]

The resistors at the ends of the N2k bus serve two essential purposes. First, they provide the intended signaling voltage across the differential signal pair: OV when not driven, and the correct differential voltage when driven. Without any termination, they system is unlikely to work at all. Second, the bus is a transmission like at the. speeds driven, and without proper termination at the ends reflections will occur that will distort signals and reduce signal integrity at the receivers.

 

[Don Crowther]

John & BrianQ
That attachment you sent cleared up alot for me Thanks
Greg and Ward H
Thanks for your input.

"Plan B would be to use the 5m backbone cable to run up to the P70s, and put a T, terminator, and short drop cable up there; connect the other end of the backbone cable to your 5-way, and add the drop for the APU, power cable, and terminator to that."


So the 5m cable could be plugged into the 5 way and the data from the p70 would transfer to the ACU? Have i got that right?

 

[jviss]

So the 5m cable could be plugged into the 5 way and the data from the p70 would transfer to the ACU? Have i got that right?

Yes, assuming you terminate the 5m cable and transition to the drop cable at the P70s, using either a T, drop cable, and terminator, or the A06074 and drop cable.

The 5-way is a backbone. The 5m backbone cable extends this. You still need terminators at the ends of the backbone.

Update: I just verified this with my box of STNG stuff. The five-way has a blue connector at each end. Put a terminator in one. Put the 5m backbone cable in the other. To one white connector put the power cable. To another the drop to the APU. At the end of the 5m cable use either a T, terminator, and short drop to the P70s, or an inline terminator connector and short drop. I just built this exact network, so I know it will all connect together.

 

[jviss]

Draw a sketch of your intended parts and cables connections, take a pic with your phone, and post it here, so we can review it.

 

[jviss]

...which reminds me, I no longer have a boat with a Raymarine STNG network, and, having installed one on my previous boat, and being the OCD nut that I am, I have a big box of 'leftover,' brand new STNG parts that I should list for sale. When presented with a 'collection' of anything, I am compelled to collect the whole set.

 

[jssailem]

Like the Rain in Spain. By Jove you got it.

 

[Don Crowther]

 

[Don Crowther]

So I need to put a terminator at the end of the 5 way bar

 

[Ward H]

So I need to put a terminator at the end of the 5 way bar

Yes, you do.
Your diagram is correct.

 

[jviss]

Yes, @Don Crowther , that looks good, as long as there's a terminator on the rightmost port of the 5-way in your sketch.

 

[jviss]

Not that people necessarily have a choice, given their choice of equipment, but a couple of things I like about Simnet vs. STNG:

• small connector - only 9mm vs. about 12mm for STNG - so, smaller hole;
• all cables are the same - drop and backbone, same connector;
• power cables with and without integrated terminators (save a port);
• 7 port ("prong") joiner;
• giblets like blanking plugs are a lot cheaper.

But, as I mentioned, I think people choose the gear they want, and have to live with that manufacturer's wiring system.