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I'm trying to set up a simple NMEA-2000 network using a Lowrance LMF-400 multi function display and a EP-60R fuel flow sensor. I've connected everything at home, powered from a small 12V battery. It worked for a while until I unconfigured the EP-60R in the "bus devices" menu on the LMF-400. Now "bus devices" is empty and I don't get a fuel flow reading. I've tried every reset-procedure and configuration I can find, but still no connection. Have anybody else had similar problems? Any troubleshooting ideas?
I've even connected an oscilloscope to the databus. There is a continuous flow of data when only one unit is connected. With both connected there seems to be some kind of handshaking first and then one data packet every second or so.
Any help is appreciated. I'm stuck.
The store I bought it is far away, so I want to be sure there is something wrong before I try to return it.
You should be able to re-configure it thru the same menus you unconfigured it I don't remember the exact details but the steps are in the manual. I just got mine installed with 2 sensors, I've only been out once for a quick trip but so far so good.
Like what pjc says. Do a bus scan and see if you can see the devices. If you can't, then you have a bus problem - power or termination. I would offer one other bit of advice re the bus setup - you NEED TO configure the bus and terminators JUST the way Lowrance says to or else you could have problems with data integrity. I tried a config they didn't specially say was wrong and it seemed to work, then it didn't. What had been working just fine suddenly went south and I couldn't see devices on the bus. I reconfig'd to exactly per the book and all was well.
Through connections and terminators on the 'sides' of the T's and devices on the 'bottom' ONLY. Also make sure you have 120ohm terminators on both extreme ends - no more or less. They should say 120 right on them. Also, check your battery. I know the bus works down to at least 11 volts.
Can I configure the bus at home (on hose power with converter), then install on boat and have it remember or is their no way the system can remember it's settings?
Can I configure the bus at home (on hose power with converter), then install on boat and have it remember or is their no way the system can remember it's settings?
Absolutely. When you shut off power in the boat it is no different than shutting off power in your house. There is non-volatile memory inside the LMF that remembers its own settings and non-volatile memory in the EP-60 that keeps track of fuel usage.
I've tried bus search and it allways return "no devices on bus".
I believe I've connected the bus correctly. 2 Ts, 120ohm terminator at one end, terminator with power at the other end. No other cables. I've tried different connections too.
The voltage is just above 13V and does not drop much under load.
I've tried bus search and it allways return "no devices on bus".
I believe I've connected the bus correctly. 2 Ts, 120ohm terminator at one end, terminator with power at the other end. No other cables. I've tried different connections too.
The voltage is just above 13V and does not drop much under load.
Ok here's some things:
1. You will NEVER be able to configure a device if the LMF can't 'see' it. It MUST see it when you do a bus scan. So that's your first problem to solve.
2. Just to make sure its right, the 'bottoms' of the 2 T's connect to devices ONLY, the 'sides' only connect to other T's or a terminator. Note that you can have an extension cable between T's, or T's can be connected directly together. In your case, the BOTTOM of one T should go to the LMF, the BOTTOM of the other T should go to the EP-60.
3. How are you supplying power? If its from a battery, then I am suspect of your 'just above 13V' since a fully charged storage battery should be around 12.6V. Please verify. If its from some sort of power supply, the power supply *may* have too much noise on it. If it does, it can cause all kinds of problems including your current problem. DO NOT USE a battery charger as a power supply - the output voltage from a battery charger can have all sorts of "electrically bad" stuff on it unless its connected to a battery. Bad enough to even blow up what its connected to. I'm not saying it does and that all chargers are bad for this use, but some are and you don't know which ones unless you specifically test them.
4. You said the voltage only dropped 'a little' with the equipment on, but where are you measuring this? If you're measuring at the battery terminals, that could be your problem right there. The voltage that is actually GETTING TO the bus needs to be at 11V or more. You need to measure the voltage AT the power wire going to the bus. Better yet, connect the power wires from the terminator right to the battery terminals. As long as you have 11V or more of GOOD power, the setup should work fine on your table.
5. You probably did this, but it doesn't hurt to repeat. Under some circumstances, you need to 'refresh' the Bus Devices List. Press MENU, select System Setup, then press Menu. Highlight Bus Devices and then press Menu. You should see the complete list of what the LMF can see.
6. Its always possible that something has failed, but I honestly think it is unlikely. Its MUCH more likely that you have a power or a connection problem.
kchace - 3/13/2008 2:20 PM
1. You will NEVER be able to configure a device if the LMF can't 'see' it. It MUST see it when you do a bus scan. So that's your first problem to solve.
2. Just to make sure its right, the 'bottoms' of the 2 T's connect to devices ONLY, the 'sides' only connect to other T's or a terminator. Note that you can have an extension cable between T's, or T's can be connected directly together. In your case, the BOTTOM of one T should go to the LMF, the BOTTOM of the other T should go to the EP-60.
I'm 99.9% sure this is right:
Quote:
kchace - 3/13/2008 2:20 PM
3. How are you supplying power? If its from a battery, then I am suspect of your 'just above 13V' since a fully charged storage battery should be around 12.6V. Please verify. If its from some sort of power supply, the power supply *may* have too much noise on it. If it does, it can cause all kinds of problems including your current problem. DO NOT USE a battery charger as a power supply - the output voltage from a battery charger can have all sorts of "electrically bad" stuff on it unless its connected to a battery. Bad enough to even blow up what its connected to. I'm not saying it does and that all chargers are bad for this use, but some are and you don't know which ones unless you specifically test them.
At first I used a small (4Ah) sealed lead battery. This worked well for an hour or two, until I tried that stupid unconfigure function(to me, this is the strangest part).
Later I have tried a regular 60Ah battery and a high quality lab supply (tried 12, 13and 15V)
Quote:
kchace - 3/13/2008 2:20 PM
4. You said the voltage only dropped 'a little' with the equipment on, but where are you measuring this? If you're measuring at the battery terminals, that could be your problem right there. The voltage that is actually GETTING TO the bus needs to be at 11V or more. You need to measure the voltage AT the power wire going to the bus. Better yet, connect the power wires from the terminator right to the battery terminals. As long as you have 11V or more of GOOD power, the setup should work fine on your table.
What I meant to say was that there is no noticable drop.
I've measured at the terminals using a digital multimeter. I didn't want to cut the cables to mesure other places. Anyway, I can't imagine a short cable like that and low currents would cause a >2Volt drop.
Quote:
kchace - 3/13/2008 2:20 PM
5. You probably did this, but it doesn't hurt to repeat. Under some circumstances, you need to 'refresh' the Bus Devices List. Press MENU, select System Setup, then press Menu. Highlight Bus Devices and then press Menu. You should see the complete list of what the LMF can see.
6. Its always possible that something has failed, but I honestly think it is unlikely. Its MUCH more likely that you have a power or a connection problem.
I've refreshed MANY times. It seems strange that something like this would just break under normal use, but right now I can't think of any other explaination.
I think I'll try to find a working network that I can connect my stuff to.
Well today, 2 hours ago, I did the same thing!!! I unconfigured my fuel flow sensor from the "bus device" list and poof it was gone!
I boated all day today with no problems at all and when I got home, I decided to play with it in the driveway. I have it hooked exactly like you. Then I was following the manual on how to configure and unconfigure. I also have the gps antenna hooked to the bus. It shows up and the "bus device" list, so its not the bus. We need to keep in contact here. I need a solution too. It's very frustrating! BTW, when you finally get it working and installed, its wonderful! Dave
__________________ Dave
2000 Regal Commadore 2660
Jensen Beach, FL
After searching the internet I saw this thread and joined the forum to get some help with the LMF-400 as well. This past winter I installed the 400 and this past week turned it on for the first time. All was well, powered up and recognized bus devices. Today as I was trying to configure I had one sensor reading flow and another very inconsistent. I actually switched the sensors from fuel line to fuel line and when I went to reconfigure I lost the ability to locate any bus devices (I have a total of three sensors, two engine and one genny. I was going to use the 3 engine/2 tank config as I have two fuel tanks). Anyway I believe I have tried everything to get the unit to see the bus devices but had no luck. Tomorrow I was going to try a hard reset, does anyone have any suggestions??
I googled and found out how to do it. So I went out in the driveway and just tried it. No luck! Somebody find out what is going on and be sure to post the cure.
__________________ Dave
2000 Regal Commadore 2660
Jensen Beach, FL
The directions (single sheet that came in the box w/ LMF 400) shows the power adapter connecting to the end of the bus network acting as the other 120 terminator and then connecting to a power source. It does state 120 on the actual piece as well. The unit is plugged into the "bottom" of a "T" as a device along with the sensors to their individual "bottom" of "T's".
If the power adaptor is a terminating power adaptor than it's OK, but if not than you need to terminate each end of the NMEA 2K bus. Total of two terminators needed and must be at the ends of the bus only.
Than I imagine the stock setup has the terminating power adapter which appears what the picture shows, so how is it the problem?
Again if it is a terminating power adaptor there is no problem. They make power adaptors that terminate and power adaptors that do not. You can not tell from the picture which one is being used.
Lowrance LMF-400 and EP-60R setup 
