Hoping someone can give me some light here. I had a 2000 network on the boat that was simple. It had an FI50, MFD, Yamaha 2000 connection, small backbone with termination on both ends.
I recently added a DST800 smart sensor, SC30 Satellite compass and an Actisense NGW 1. I purchased a Furuno F!5002 which is a NMEA 2000 junction box. I has a power port, 6 2000 ports for connection and two backbone connectors if you choose to use them.
So I hooked up the SC30, FI50, Yamaha, MFD and NGW 1 to 5 of the six ports. My DST800 cable wasn't long enough to reach the junction box so I ran a Mid cable from one of the backbone ports (resistor off for that port) to a drop tee and hooked the DST800 to the tee. Here's where I made one mistake, I forgot to put the terminator on the other end of the tee.
I then hooked up the power port to a switched 12v connection, double checked to make sure the wires were all correct and hit the power. I immediately started seeing smoke and before I could even turn the switch off the board fried on the FI5002.
I know all my connectors were hooked up right and the only thing I can find that I missed was the termination resistor on the backbone cable to the DST800.
So what would cause this? Can not having a terminating resistor cause this to happen?
The lack of a terminator would not cause smoke.
Nothing jumps to mind, except to wonder if in addition to what caused the problem you have a second problem in that a properly sized fuse on your power cable is absent. I would have expected a fuse to go first before you had a chance to turn off the power.
I agree. It's not a terminator problem. I've often started up N2K test networks without proper termination, and hot swapped devices and terminators, all without problems.
There seems to be something wrong with your power wiring, or maybe a power flaw in one of the new devices, plus -- as Dan noted -- questionable fuse protection.
Ben and Dan,
Thanks for the comments. I figured as much about the terminator but having not dealt with them much wasn't sure.
The breaker I had it wired to was a 10amp which was my mistake. The F!5002 is rated for 2amps. So I'm sure that's why the board fried.
I know the power connector is hooked up right. So it sounds like I either have a power flaw in one of the new devices or there was a flaw in the power connector on the FI5002. More research today.
Thanks again.
Jeff, you might want to consider using a DevicePort breakout box in place of the Furuno junction box or Actisense's similar version. DevicePort is the industrial automation Canbus system from which N2K was derived, and I've had good success with boxes like these:
http://bit.ly/d6aGKo
They come in 4-, 6-, and 8-port versions, have metal connector threads (Ben!) and are built to be driven over. Upsides over the Furuno, etc. are: no cutting of cables required, no fiddly terminal blocks, no power needed, and the price (on eBay) is about half or less per port.
Unlike your 5002 and the Actisense box, these units do not form part of the backbone. Instead they hang off a backbone T, allowing you to create a star-on-backbone configuration which is very structurally convenient (and may have some cable impedance benefits, as Ben has noted in the past). Note that Maretron offers a 4-port box of this type which they source from a German manufacturer, so the concept is totally legit. The C2 version in the link above includes an attached 2M micro drop cable which connects to the T; there is also a D5 type that has a male port for connecting via your own drop cable of arbitrary length.
Well I found out what the problem was. The FI5002 12v connection was backwards. Not because of an error in how I wired it though. I had wired the 12v connection exactly as outlined in the schematic for the FI5002 that's in the FI504 manual. Turns out that schematic is wrong. I also found out that I was supposed to have a wiring diagram in my FI5002 box which I didn't have.
After pointing out the error on the schematic, Larry at Furuno told me to send it back and they would replace the unit.
Larry and the rest of the techs at Furuno are some of the nicest most helpful tech support people I've ever encountered and they speak english.
Agreed. Larry has been very patient with an endless stream of emails from me about various NavNet 3D integration issues.
Will an N2K pro will validate my new N2K / Simnet setup as described below before I apply power. Thanks, Brian
I have routed all the various cables to my lower helm and brought them together at a 7 port Simnet bridge as here:
1. network power via simnet cable
2. simnet adapter to n2k DST800 transducer
3. simnet adapter to n2k PB200
4. simnet to Simrad NSE8 [also ethernet to nse12 topside]
5. terminator resistor
6. simnet adapter to n2k actitense NGT-1
7. unused and empty.
My Simrad radar is connected to the NSE8 via ethernet. My VHF/AIS talker is connected to the topside NSE12 via the combined n0183 / video in port. That nse12 is also outputing a mirror image with dvi to a monitor down below.
I am a neophyte on this networking stuff but it appears that the N2K 'backbone' is the simnet bridge itself. Does that make sense?
I think that's going to work OK, even though there only seems to be one terminating resistor. I read the SimNet install manual recently, and noted that Simrad is comfortable with single termination on a small network.
However, I'd be tempted to put terminators at ports #1 and #7 so the Multiport looks more like the N2K backbone it is.
Thanks Ben. Will do. I hope to meet you in Camden this summer and you will come aboard to see my nav setup. My son Kevin is a pediatrician there. Brian
"DevicePort is the industrial automation Canbus system from which N2K was derived", Do you mean DeviceNet? The NMEA has added a layer of control above the DeviceNet spec so there is more to it that simply building a DeviceNet network. Canbus networks are typically used in industrial settings or in the automotive industry where engineers set-up the systems. These system are designed before installation and recorded for future expansion, unlike most consumer and even installer created networks on their yachts. Coming to retrofit someone else's undocumented bus would be easier if the additional rules of the NMEA were implemented. NMEA 2000 needs tighter regulation because the systems need to function as plug and play with novices building networks as well as professionals. So the NMEA have made things more strict to protect the user not to make life more difficult.
"Instead they hang off a backbone T, allowing you to create a star-on-backbone configuration which is very structurally convenient." It may be convenient but it breaks the NMEA 2000 rules.
Hang on, Actisense; the multiport Adam discussed is not daisy chaining and is NMEA 2000 legal, as long as the drop to it plus its own longest drop to a device do not exceed the N2K maximum drop length. In fact, Maretron seems to favor multiports like this now, because they remove the slight impedance distortion of the equivalent tees from the backbone.
Daisy chaining is when a drop runs through a device, and its danger is debatable, as discussed here:
https://www.panbo.com/archives/2009/12/furuno_fi-50_multi_xl_a_nmea_embarrassment.html
What Ben said! But you are right that I meant DeviceNet. DevicePort is, I think, Allen-Bradley's trademark.