Question about departing the pitot way of life

[ZZ13]

Now that my audio issues are resolved its onto the speedometer. The pitot path is completely unreliable with my Smartcraft speedo. I'd like to join to the GPS world. According to my documentation the SC1000 speedo has a NMEA input interface (2 wires, blue and white) and my Raymarine SL70CRC has a NMEA output connector with pins 2 and 3 as NMEA_SIG and NMEA_GND. Is it just a matter of connecting those two together to get GPS into the speedometer? I have not dissected the dash yet to make sure the NMEA interface on the speedo isn't connected to anything. But base on its response to the CAL settings I try, it is not connected. Thanks in advance.

 

[Henry Boyd]

Now that my audio issues are resolved its onto the speedometer. The pitot path is completely unreliable with my Smartcraft speedo. I'd like to join to the GPS world. According to my documentation the SC1000 speedo has a NMEA input interface (2 wires, blue and white) and my Raymarine SL70CRC has a NMEA output connector with pins 2 and 3 as NMEA_SIG and NMEA_GND. Is it just a matter of connecting those two together to get GPS into the speedometer? I have not dissected the dash yet to make sure the NMEA interface on the speedo isn't connected to anything. But base on its response to the CAL settings I try, it is not connected. Thanks in advance.

Its almost that simple. I connected the System View SC5000 to our old RL70CRC. You may need to get a SmartCraft 'harness' with a built in resistor. I needed to do that with both the RL70 and its C80 replacement. Mercruiser CS should be able to tell you what part you need, or if you even need the resistor NMEA harness. On the harness I got, the resistor was attached right up at the plug, so you can't just buy the resistor harness and then cut it off if you don't need it.

The other thing you will have to do is go into the RL70 set up menu and turn on NMEA output, then you will need to turn on/off all of the NMEA 'sentences' you need/ don't need. You only want to export the data strings the SC1000 can understand, otherwise you confuse the little guy.

Henry

 

[ZZ13]

Thanks, Henry. I sent an inquiry to Mercruisier support.

 

[Woody]

Henry, do you have a pic of your helm showing your C80? I've been hesitant to put radar on my boat thinking there was no good place on the dash but it sure would be nice sometimes when I'm in the fog.

 

[Henry Boyd]

Woody,

Here are a couple pictures. Unfortunately I was taking pictures of the dash panels I made to accommodate the SC5000 display, so the radar is kind of out of sight. I drive standing so there is no block to my view.

Henry

 

[ZZ13]

Looks great, Henry. FYI, I started tracing the speedometer cabling and SL70CRC NMEA out to find their ends. The good news is there is a cable connected to the NMEA out connector on the SL70CRC. But I haven't found the end of it yet. It goes along the helm and then appears to wrap around to the starboard channel. I'll have to remove a speaker and maybe the sidepanel with the cupholder to continue tracing it.

 

[ZZ13]

I almost have this worked out. I talked to Mercruiser and I don't need any special cable with resistors. That is only required it you have System View. Mine will be a straight butt connection. I found the speedometer NMEA wires and they indeed are capped off and not connected to anything. The SL70CRC NMEA out cable is about 5 feet long and I have traced the first 3 feet of it, then it disappears from my access. So I will most likely buy another cable online (found them for $22 on ebay) and just unplug the current one and run the new one to the speedometer. My other option is just to cut the current SL70CRC cable at the 3 foot mark and reroute it to the speedometer. I am almost 100% sure it isn't connected to anything, but a new cable would at least allow me to restore the original wiring should I find it is being used for something (can't image what).

 

[2000SEARAY280SS]

Prior to cutting the cable if you just disconnected it you would discover if it is connected to something on the other end. If you lose a sensor on your display you would know.

Often vendors provide extension cables so your 5 foot cable may actually be much longer and connected to something like a GPS or depth sounder.

 

[ZZ13]

Prior to cutting the cable if you just disconnected it you would discover if it is connected to something on the other end. If you lose a sensor on your display you would know.

Often vendors provide extension cables so your 5 foot cable may actually be much longer and connected to something like a GPS or depth sounder.

That's a good idea. I found a used cable on ebay that I just bought for $9. I'll unplug and run for a while and see if anything looks screwy. If not then I'll plug the new one in and have at it. The cable I am replacing is an output cable, not an input cable. The GPS comes into the SL70CRC via a different cable. So, I don't expect anything to not work when I unplug it, but we'll see.

 

[ZZ13]

Its almost that simple. I connected the System View SC5000 to our old RL70CRC. You may need to get a SmartCraft 'harness' with a built in resistor. I needed to do that with both the RL70 and its C80 replacement. Mercruiser CS should be able to tell you what part you need, or if you even need the resistor NMEA harness. On the harness I got, the resistor was attached right up at the plug, so you can't just buy the resistor harness and then cut it off if you don't need it.

The other thing you will have to do is go into the RL70 set up menu and turn on NMEA output, then you will need to turn on/off all of the NMEA 'sentences' you need/ don't need. You only want to export the data strings the SC1000 can understand, otherwise you confuse the little guy.

Henry

I got my SL70CRC NMEA out wired to the SC1000 speedometer. I can't get it to work. I do not have System View, just the gauges. I am confused in several areas:

1) Smartcraft complete guide says my Raymarine uses version 2.0+ of NMEA 0183 and that the Smartcraft supports version 1.5 and version 2.0 with GSV and VTG sentences disabled. It implies version 2.0 only is supported if you have System View (which I don't). Anyone know if the Smartcraft SC1000 speedometer without System View will accept version 2.0 of NMEA 0183? If not, then my project is done and now I know why it was never connected at the factory.

2) The Raymarine SL70CRC manual implies that the NMEA out is enabled just by a power on of the display. The system setup screen then lets you selective turn on/off individual NMEA sentences. It does not indicate there is any kind of a master "enable NMEA out". Henry, your post indicates there is such a master NMEA out switch. Did I misinterpret your statement? If not, where is the master setting? Also, is there an easy way to tell if data is coming out of the Raymarine (using a voltmeter or something?)?

Thanks in advance.

 

[Henry Boyd]

I got my SL70CRC NMEA out wired to the SC1000 speedometer. I can't get it to work. I do not have System View, just the gauges. I am confused in several areas:

1) Smartcraft complete guide says my Raymarine uses version 2.0+ of NMEA 0183 and that the Smartcraft supports version 1.5 and version 2.0 with GSV and VTG sentences disabled. It implies version 2.0 only is supported if you have System View (which I don't). Anyone know if the Smartcraft SC1000 speedometer without System View will accept version 2.0 of NMEA 0183? If not, then my project is done and now I know why it was never connected at the factory.

2) The Raymarine SL70CRC manual implies that the NMEA out is enabled just by a power on of the display. The system setup screen then lets you selective turn on/off individual NMEA sentences. It does not indicate there is any kind of a master "enable NMEA out". Henry, your post indicates there is such a master NMEA out switch. Did I misinterpret your statement? If not, where is the master setting? Also, is there an easy way to tell if data is coming out of the Raymarine (using a voltmeter or something?)?

Thanks in advance.

You will need the resistor harness. I spoke to Mercruiser last week regarding integrating SC with the new AIS & DSC VHF and they confirmed that the resistor cable is needed for SC to work from a Raymarine source. The lack of resistor causes SC to lose the connection to the Ray MFD

I seem to remember that there was a single switch to enable NMEA out, as well as individual switches for each sentence. But I set up the RL70 four years ago and don't have it, or any of the documentation anymore.

Have you tried reversing the NMEA wires?
What baud rate is the NMEA out set at? SC will only accept 4800. I learned last week thatNMEA can be transmitted at multiple speeds. On the C80 the NMEA port speed can be adjusted. I don't know / recall if this was the case on the RL 70, but if there is a choice make sure it is set to 4800.

Henry

 

[ZZ13]

You will need the resistor harness. I spoke to Mercruiser last week regarding integrating SC with the new AIS & DSC VHF and they confirmed that the resistor cable is needed for SC to work from a Raymarine source. The lack of resistor causes SC to lose the connection to the Ray MFD

I seem to remember that there was a single switch to enable NMEA out, as well as individual switches for each sentence. But I set up the RL70 four years ago and don't have it, or any of the documentation anymore.

Have you tried reversing the NMEA wires?
What baud rate is the NMEA out set at? SC will only accept 4800. I learned last week thatNMEA can be transmitted at multiple speeds. On the C80 the NMEA port speed can be adjusted. I don't know / recall if this was the case on the RL 70, but if there is a choice make sure it is set to 4800.

Henry

Thanks. There is no baud rate setting or master turn on setting on my SL70CRC, that I can find in any of the documentation. I just read all I could about NMEA and now that I see its just a 4800 baud serial interface pumping out ASCII strings, I can figure out how to look at the data.

I did try reversing the connections - no change. I'll try to locate a resistor harness (is this hard to find, according to the Smartcraft Complete Guide its p/n 84-88951A02) and give that a try. Looks like the SC1000 only needs the RMB and RMC signatures to get the time, SOG and waypoint data it uses. I think those are the only sigs I need to turn on.

 

[ZZ13]

I did some searching on cable part 88951A02 that is listed in the Smarcraft Complete Guide. It is a 500 ohm resistor cable that is to be used for data devices with high impedence on the NMEA 0183 data line. Most importantly, I found out that there is a typo in the guide regarding the part number. Its actually 8889515A02. Found it online for $17. Wonder if just putting a 500ohm resistor inline on the NMEA+ data line would do the same thing.

According to the illustration of the cable it has a connector on one end. Both my Smartcraft NMEA lines and the Raymarine NMEA lines are just open ended wires. Where would this connector plug in?

 

[Henry Boyd]

On the SC 5000 harness it has a plug connection. Worst case I suppose would be you nip the plug off and connect the proper wires.

Henry

 

[ZZ13]

I actually got some encouragement on this today. I had a 500ohm resistor laying around so I rigged it up to the cabling. When I turned on the ignition switch to power up the Smartcraft, the speedo displayed "updating time from GPS", and set the clock via the GPS input. Yippee, said I. Interesting, though, I could still set the time manually using CAL1, and the Smartcraft manual says this manual setting is disabled when time is read via GPS. Then I shut everything down and unplugged the NMEA cable from the Raymarine to make a more permanent run for it. When I plugged it back in and turned everything back on, nothing worked again. Now I am starting to think the used NMEA cable I got may have unreliable worn connectors on it. I may just buy a new NMEA Raymarine cable and the Smartcraft resistor harness and start all over with know good cabling. Now I know it can work, at least.

 

[ZZ13]

Well, I finally got this NMEA connection from the SL70CRC to the Smartcraft speedometer working. I'll save you the details on how I figured this out, but it turned out to be that the contacts on the SL70CRC NMEA cable's plug were recessed too far into the connector for the mating pins. I shaved off all the rubber back to the front of the contacts and it fits nice and snug now and makes good contact. I did not need the resistor harness for the SC1000. It did turn out to only be needed for Smart View. I turned on only the RMB and RMC signatures. I haven't taken the boat out yet, but in the slip I verified it loads time from the GPS, it accurately reads and displays the COG and the distance to the next waypoint. I can't check the GPS speed or the fuel to waypoint until I go for a ride. The digital readout for MPH now also displays a little "gps" next to it. I did try the SL70CRC in simulator mode and the speed shown on the simulator did not display on the speedometer. I am hoping the SL70CRC does not transmit out the NMEA interface in simulator mode, or else I may also have a bad speedometer. Its never displayed the speed since I got the boat and the pitot sensor was replaced last year and the shop claims the pitot tube is clear.

One question, does the Smartcraft speedometer move the needle to the speed when in GPS mode, or does it only display the numerical speed on the display?

Next is to add a third leg to this NMEA circuit to go to the Ray215 VHF so I can get lat/long for distress calls (I'll need to turn on the GLL signature for that), and to get it to quit alarming me that there isn't NMEA attached to it.

Thanks for everything Henry.

 

[ZZ13]

To polish of this thread, all the NMEA devices are now wired together and all work beautifully with the new data they have available. It turned out to be a very simple solution, where I was chasing ghosts due to bad contact between the NMEA cable connector and the chartplotter. Took a ride today and it was a joy to finally see the Smartcraft speedometer needle move. It also accurately displayed all the waypoint data. And the Raymarine 215 VHF doesn't alarm me anymore that no NMEA lat/long data is available to it.