Lowrance HDS7 displaying incorrect engine temperatureon my Yamaha F150

[boscoe99]

And good point Yam... Guages are there to teach you what is normal! So that your brain can immediately recognise what is not normal .

99yam usually has good points.

With respect to a gauge indicating what is normal, can the needle just point to a general position on a scale (ala the Yamaha Command Link bar scale where sometimes it is on the middle bar and sometimes is on a bar or two up the scale, all positions being considered normal) or does it need to be precise to the degree F?

I suspect some will want it to be precise to the tenth of a degree F. A degree C by the way not having enough desired resolution.

I have three digital thermometers (all same brand and model) here in my house which read outside temperature to the tenth of a degree F. They never report the same temperature. Do I need to register a complaint with the manufacturer?

[zenoahphobic]

99yam usually has good points.

With respect to a gauge indicating what is normal, can the needle just point to a general position on a scale (ala the Yamaha Command Link bar scale where sometimes it is on the middle bar and sometimes is on a bar or two up the scale, all positions being considered normal) or does it need to be precise to the degree F?

I suspect some will want it to be precise to the tenth of a degree F. A degree C by the way not having enough desired resolution.

I have three digital thermometers (all same brand and model) here in my house which read outside temperature to the tenth of a degree F. They never report the same temperature. Do I need to register a complaint with the manufacturer?

Personally perhaps several positions so that a transition or movement can be seen. You don't have to be anal about parts of a degree or even several degrees. Yes you still need to know actual degrees so that you can remember what it is all about and have something to compare to. That is why units of measurements have been formulated.

Your thermometers and everybody else's thermometer will read differently ( more so the lower the fraction) because they will occupy a different part of space and the particular "thing" you are measuring is in a constant state of change (energy shifts manically).
And all devices that measure, inherently take some of the "stuff" away.
When you go smaller things become hectic; go really small and you will find that there really is nothing there! (Atomic physics).

An example like fire danger ratings is useless unless you knew what is high, very high, extremely high, catastrophic high.....
Similarly a person might say at MarbleBar that it is quite warm, another in Iceland using the same sentiment. One would not have a clue if you didn't realise the former was in 45 degrees Celsius, and the later might be at minus 45 degrees!!!

[scottcmb1965]

Memory is a little fuzzy since it was 6-years ago. When I first hooked up my N2K to the Yamaha Command Link I used a home made jumper between the Yamaha Hub and my N2K backbone. I also had terminating resisters on both systems, I think 2 on each. I had problems with the data transfer to N2K until I changed to the Yamaha Command Link Plus gauge and kept one Yamaha hub (had two) CL to feed the N2K one hub CLP for the Yamaha Display.

I don't know what YDS would show since the eBay one available will not work on the F250XCA (Offshore model). But the CLP gauge the Garmin and the Lowrance all show the same data.

Is there any guidance included with the Lowrance cable on terminating resistors?

The only guidance Lowrance states is that there has to be terminal resistors at both ends on the NMEA backbone, Yamaha also states the same for the Command Link hub system.

Scotty

[scottcmb1965]

The thing to keep in mind is that the OP doesn't primarily want to replicate the Yamaha alarm points and shutting down to idle, he wants an earlier warning, or atleast see the change that may alert him to go a little easier not at limp mode to a place where he can investigate.

Two , I've never needed to heat a thermal device past water boiling point. Using oil ( what type?) and a flame heater might be a bit risky.

Three, I too although ignorant worry about the bus, hubs and terminator resistor combination. Would it be helpful to alter the position of the temp on the bus? Could it be possible that this bus is overloaded? Too many devices? Try removing one or more and see what the temp does?

Its nice to see someone understands where i am coming from

As to your number 3 question. I had thought of that and disconnected the HDS NMEA2000 engine interface cable link from the Yamaha hub system and plugged it directly to the motor........ The result was still the same problem...... so that in my mind rules out the Yamaha hub system being the problem.

Cheers scotty

[tmann45]

I think that having both the CL hub with two resistors and the NMEA 2000 network having two resistors would not be kosher. My recollection is that when using the CL hub without the Gateway then one of the Hub resistors needs to come out and so too does one of the resistors in the NMEA 2000 network.

That is what makes sense to me, even though the two "backbones" are not connected in a linear fashion, the system only needs 2 resistors.

[zenoahphobic]

That is what makes sense to me, even though the two "backbones" are not connected in a linear fashion, the system only needs 2 resistors.

Way off the top of my head, what is the purpose of these resistors ? (and what are their measured values?)

If I think of wave propagation, an open ended pipe reflects some of the wave back out of sync having the affect of attenuating or cancelling some of the wave. Conversely, if a wave hits a solid wall (say resistor) the reflection adds to the original wave (look at waves hitting a rock wall how the waves get bigger nearer).

Very simply in an electrical small signal circuit, if I got this around the right way, a signal on a bus(long wire?) may be interfered with without a resistor at it's end by the neutralising affect of it's reflection .

[RayBersch]

Way off the top of my head, what is the purpose of these resistors ? (and what are their measured values?)

If I think of wave propagation, an open ended pipe reflects some of the wave back out of sync having the affect of attenuating or cancelling some of the wave. Conversely, if a wave hits a solid wall (say resistor) the reflection adds to the original wave (look at waves hitting a rock wall how the waves get bigger nearer).

Very simply in an electrical small signal circuit, if I got this around the right way, a signal on a bus(long wire?) may be interfered with without a resistor at it's end by the neutralising affect of it's reflection .

I just lost interest, but I am glad you're having fun with it!!

[zenoahphobic]

Well we are focusing on electronics at the moment