VesselView instead of N2K Gateway?

Michael T

Neither Steve. I'd have one of those new turbo-diesels if I could afford one - and none would bash you!....just havin' fun :-)

Dream_Inn

Handymans342 said:

You bashing me MT or my boat? 

Does it matter which?

Handymans342

DI, according to Raybo (who doesnt know the definition of bashing) it does.

raybo3

Really Steve??? Because I said you amuse me I was bashing you?????? Obviously you don't know what it means..........lol You crack me up bro.... I would love to sit down with you and have some Watermelon Mai tai's...........

Stodge

diggin2day1 said:

What is more to break? The analogue gauges are getting their information from the same sensors as the VesselView.... The information is being transferred to the guages via wire/cables which is same as VesselView.... Analogue gauges transform that electrical signal into usable/readable information same as VesselView. 

Not exactly.  The vessel view is getting the data from the computer on the motor.

diggin2day1

Stodge- and where does the computer on the motor get its information from? ...Sensors? I'm not being a wise-a$$... Just trying to make sense of this myself. 

Stodge

I had to think about that for a second.  

I would think there are some kind of sensors feeding the computer, but not sure if its the same ones feeding the analog gauges.  For that matter the analog gauges may be smartcraft, in which case they are using the same data as the VV.

Since I can get GPH from the computer which it figures out since it controls the fuel injectors in my mind there was some other source for the temps etc.  Just like how does it get the water pressure in the drive system?  

So you are most likely correct.

Michael T

Water pressure in the 8.2 Mags comes from sensors. I know as I had to replace one.

LaRea

Well, most of the information comes from analog sensors.  Here's a simplified explanation - please correct any errors:

Sensors connected to the engine typically include:

Exhaust Manifold Coolant Temperature Sensor (EMCT)

Oil Pressure Sensor

Manifold Absolute Pressure Sensor (MAP)

Manifold Air Temperature Sensor (MAT)

Seapump Pressure Sensor

Engine Coolant Temperature Sensor (ECT)

and more ...

These sensors all generate analog voltage signals.  

Many times per second, the engine computer digitizes the analog signals (converts the voltages to numbers).  That digitized information is what the engine computer uses to control the engine. 

There are two ways to transmit sensor signals from the engine to the helm: analog or digital.

1) Analog. The engine wiring harness has plugs with raw voltage signals for water temp, oil pressure, battery voltage and tach.  Cables connect these plugs to the helm gauges, which convert the voltages to needle positions.  If there are problems with the wiring or gauges, the needle positions can be wrong, and the captain receives bad information.  

2) Digital. The engine computer continuously writes selected sensor information to a special network called the Control Area Network (CAN) bus, a.k.a. SmartCraft.  It also writes derived information such as fuel flow rate and engine hours.  If you have VesselView or something similar, the CAN bus is where it gets all of its data.  There's no way the display can be incorrect.  You see exactly what the engine computer sees. 

Of course, not all sensors go through the engine computer.  Tank levels, trim position and tab position usually come from separate analog sensors that connect directly to the helm gauges.  However, it is possible to feed these sensors directly into the engine computer and display them with VesselView.  Same with generator data and lots of other stuff.  

An "all digital" helm means all sensor data gets digitized and written to the CAN bus, and from there you can display it however you want. 

diggin2day1

Awesome info right there!!! Thank you LaRea... 

Handymans342

I thought all sensors sent an ohm signal? Are the sensors millivolt now Larea?

raybo3

An ohm is a measure that is converted into a analog signal. Digital is a discrete signal (like on/off) 

LaRea

Right, Handy - most are actually resistive sensors.  The fuel sender is a good example.  The resistance across the sensor is 10 ohms when the tank is full, and 73 ohms at empty.  

However, what the engine computer actually measures is volts, not ohms.  It sends 5v to the sensor's input wire, and measures the voltage on the output wire (scaled by a second resistor). 

Other sensors produce a binary (discrete) output - either open or closed, which gets digitized as one or zero.  And the tach is a totally different beast -- probably a counter on the crankshaft or something like that. 

LaRea

Veering back to the original topic:

The Smartcraft Gateway is basically a 1-way network bridge.  It reads data sentences from the CAN bus, and writes them to the NMEA 2000 (N2K) network used by the chartplotter, autopilot and whatever other instruments you might have.