Electronics -- System Architecture

[Sandero]

Salty raises some interesting points. Am to understand that one shorted cable takes down the entire network?

I am not an EE... but am wondering when all this wire will be replaced by a wireless network?

Wouldn't it make sense to have wireless transducers with displays which could have easily upgradable software to display input from any transducer?

Am I crazy or what?

[goboatingnow]

Originally Posted by defjef

Salty raises some interesting points. Am to understand that one shorted cable takes down the entire network?

I am not an EE... but am wondering when all this wire will be replaced by a wireless network?

Wouldn't it make sense to have wireless transducers with displays which could have easily upgradable software to display input from any transducer?

Am I crazy or what?

Yes a short in the data wires disables the whole bus. More awkwardly in a long possible bus like 2k finding the short can be difficult and or time consuming.

Dave

[lateral]

All the more reason to have separate engine temp alarm + backup. I have the standard Yanmar alarm + engine guardian to go in. Don't know how it will handle the marine environ tho'.

[Dockhead]

Originally Posted by lateral

All the more reason to have separate engine temp alarm + backup. I have the standard Yanmar alarm + engine guardian to go in. Don't know how it will handle the marine environ tho'.

The Maretron Yanmar harness adaptor taps, but does not disable the original freestanding gauges and buzzers. I will leave those in place.

[DeepFrz]

Yes, I will install a cooling water flow alarm, but freestanding.

That makes sense.

[Beausoleil]

.delete

[Beausoleil]

Originally Posted by Dockhead

For $89 -- good plan! I didn't realize how easy it is to make these old instruments play with N2K.

I'd double-check that. The adapter is Seatalk to SeatalkNG, not to N2K. SeatalkNG cables combine Seatalk wiring with SeatalkNG wiring in the same cable. I believe that is what you get for $89. The adapter does not convert Seatalk protocol to SeatalkNG protocol or to N2K protocol. Your Raymarine MFD does that...

[chala]

Originally Posted by Beausoleil

combine Seatalk wiring with SeatalkNG wiring in the same cable.

I do not think so
(The SeaTalk – SeaTalk ng ng converter allows connection of a range of SeaTalk compatible products to the SeaTalk ng network. It contains electronics to bridge communications between the 2, allowing information to be shared. Quote Raymarine )
for the reason that it does not convert all ST1 into STng for instance, Classic c series autopilot control communication in ST1 with the auto pilot STng is not converted and vice versa not to some extent. If it was a wiring continuation then I would expect that all ST1 data would be available in STng.

Originally Posted by chala

A Seatalk to Seatalk ng converter will bridge Depth, speed, wind etc- MOB- Heading- GPS- Navigation data (waypoint information)- Rudder angle. At around $120 the converter kit is good value because it contain 3 cables, 2 plugs and 2 terminators.

Originally Posted by chala

Update. When a ST1 to STng converter is used and the autopilot is connected to an MDF using STng the data from the pilot should not be sent via ST1 and the converter to the MDF because the same data is also sent via STng. This create two sources of the same data to the MFD from the pilot or from the pilot to the MFD. The data from the converter may be slower and may create some malfunctions in the system.

Note: when installing the converter if the LED indicator of the converter is easily visible, it will help checking ST1 and STng status.
This product is subject to constant up grade and what is valid today may may not be tomorrow.

[goboatingnow]

Originally Posted by chala

I do not think so
(The SeaTalk – SeaTalk ng ng converter allows connection of a range of SeaTalk compatible products to the SeaTalk ng network. It contains electronics to bridge communications between the 2, allowing information to be shared. Quote Raymarine )
for the reason that it does not convert all ST1 into STng for instance, Classic c series autopilot control communication in ST1 with the auto pilot STng is not converted and vice versa not to some extent. If it was a wiring continuation then I would expect that all ST1 data would be available in STng.




Note: when installing the converter if the LED indicator of the converter is easily visible, it will help checking ST1 and STng status.
This product is subject to constant up grade and what is valid today may may not be tomorrow.

None of this bothers Dockhead, he justs wants to bridge basic ST60 info and the convertor is the easiest way to do it.

Dave

[chala]

Originally Posted by Dockhead

Has anyone noticed the autopilot controls on these new plotter? These are the dog's danglies! I could seriously contemplate doing without a separate pilot control at the helm -- the plotters have dedicated buttons for engaging and disengaging the pilot.

On the paper it may looks goods, in practice it may not be so simple. For instance if you initiate a Goto (waypoint or cursor) on one MFD and cancel it on an other MFD (Stop Follow) it may leave a ghost waypoint (waypoint number, distance to waypoint, bearing to waypoint) on the autopilot control head (reside in autopilot computer). Trying to Track this way point will result in a warning No Data. Initiating an other Goto will make the ghost to disappear and the autopilot to work properly. Depending on which MFD the Stop Goto or Stop Follow is initiated, the ghost may disappear, reappear, or be replaced by another ghost. Normally the ghost is only an annoyance and does not affect the running of the autopilot. To get rid of it, it is necessary to find out which MFD produce the ghost and remove it by a Stop Goto.
So is Raymarine system.
May be your Zeus may not produce ghosts, let us know.

Originally Posted by defjef

Salty raises some interesting points. Am to understand that one shorted cable takes down the entire network?

The installation of a STng like any other installations will prove to be reliable if done properly and operated in accordance with the manufacturer specifications. A balanced installation as recommended by Raymarine with a MFD in each branch may offer more dependability.

[DotDun]

Originally Posted by chala

The installation of a STng like any other installations will prove to be reliable if done properly and operated in accordance with the manufacturer specifications. A balanced installation as recommended by Raymarine with a MFD in each branch may offer more dependability.

While this is true, it doesn't address the symptoms to a bus network when something not 'in accordance with the manufacturer specifications' happens, like a shorted cable due any of a variety of things that can happen on boats.

So, you install the cabling properly, but couldn't see that inside the mast the cable gets pinched between the mast and halyard. As the halyard chafes the cable over time it eventually shorts the data conductors. Now you have periods of no data/some data/working properly depending on heel, humidity, etc. Troubleshooting a bus network several years and modifications after original installation is huge PITA.

So yes, the statement is true, if the cable doesn't get damaged and all devices behave properly (which adheres to 'in accordance with the manufacturer specifications'), there is a good chance a bus network will operate properly for years.

[colemj]

Originally Posted by DotDun

While this is true, it doesn't address the symptoms to a bus network when something not 'in accordance with the manufacturer specifications' happens, like a shorted cable due any of a variety of things that can happen on boats.

So, you install the cabling properly, but couldn't see that inside the mast the cable gets pinched between the mast and halyard. As the halyard chafes the cable over time it eventually shorts the data conductors. Now you have periods of no data/some data/working properly depending on heel, humidity, etc. Troubleshooting a bus network several years and modifications after original installation is huge PITA.

So yes, the statement is true, if the cable doesn't get damaged and all devices behave properly (which adheres to 'in accordance with the manufacturer specifications'), there is a good chance a bus network will operate properly for years.

The last statement you make can be made for every single system on a boat - inverters, watermakers, alternators, solar, etc. If installed properly with no damage, they operate for years.

I don't really understand why people are so worried about N2K cabling. Yes, something could go wrong like in every other system on a boat, but then troubleshooting and repair takes place, like everything else.

And for most of us with small N2K networks (meaning anything less than a megayacht), troubleshooting cable problems is very easy.

In the example of a chafed mast cable, one simply unplugs it where it enters the boat and plugs in a terminator if required. If one doesn't know where the problem is, then it is a very easy thing to unplug things and isolate branches until you find it.

So far, the installation ease, performance, reliability and troubleshooting of our N2K system is miles better than it was with our old 0183 system. 0183 is terrible for installation, performance, troubleshooting and reliability. While the N2K topology may not be ideal, it makes 0183 look like alchemy.

And that is if you installed the 0183 system personally. Trying to suss out a 0183 network that has been installed by someone else and added to or modified over the years takes a long armed small alchemist monkey with a Ph.D.

And good god, reading the Seatalk threads makes that seem impossible in comparison to even 0183, let alone standard N2K.

Yet many people see Seatalk and 0183 as acceptable rugged standards, while fearfully viewing N2K as new, unproven and fragile.

I just don't get it.

DISCLAIMER: I'm all in favor of a better physical topology for N2K - I just don't see the widespread problem of the current one, particularly in light of the systems it replaces.

Mark

[DotDun]

Originally Posted by colemj

I just don't get it.

DISCLAIMER: I'm all in favor of a better physical topology for N2K - I just don't see the widespread problem of the current one, particularly in light of the systems it replaces.

Mark

We're not in disagreement.

I'm simply citing years of experience troubleshooting bus networks. And regardless of what you think, one's recollection of where/how wires run years after installation never quite matches reality.

[DeepFrz]

And regardless of what you think, one's recollection of where/how wires run years after installation never quite matches reality.

Hence the need for wiring diagrams and install notes that are updated religiously.

[K_V_B]

Originally Posted by defjef

Salty raises some interesting points. Am to understand that one shorted cable takes down the entire network?

It's one of the reasons why computer networks have abandoned bus topologies two decades ago...

You can implement N2K in a sort of star topology, using a multi port box, but those are passive devices. An active N2K hub could be a useful device.