Interface Cetrek 737 to MFD

[Dazzajohm]

I’ve got a Cetrek 737 Autopilot and a Raymarine E7d MFD and I was wondering if there was any way to interface the two as I know the mfd is able to control an autopilot. I’ve got the Cetrek manual which talk about connecting it to external devices using NMEA 0183 but doesn’t really say more than that.

Has anyone managed to do this?

 

[prv]

The plotter won't fully control the pilot (as in, engage/disengage, select operating mode, adjust course in heading-hold mode, etc) since there are no common standards for those. However, when on track between two waypoints it should emit track data for the autopilot - if placed in track-hold mode via its own controls - to follow. How useful that is to you depends on how you tend to sail and navigate.

The specs for the e7D say it has one NMEA0183 output so you should be able to connect them; if you already have a DSC VHF being fed by the plotter then you'll need to wire in parallel with that but it shouldn't be a problem - in fact it may help as it means you don't need to track down a proprietary Raymarine plug for the plotter

Pete

 

[Dazzajohm]

The plotter won't fully control the pilot (as in, engage/disengage, select operating mode, adjust course in heading-hold mode, etc) since there are no common standards for those. However, when on track between two waypoints it should emit track data for the autopilot - if placed in track-hold mode via its own controls - to follow. How useful that is to you depends on how you tend to sail and navigate.

The specs for the e7D say it has one NMEA0183 output so you should be able to connect them; if you already have a DSC VHF being fed by the plotter then you'll need to wire in parallel with that but it shouldn't be a problem - in fact it may help as it means you don't need to track down a proprietary Raymarine plug for the plotter

Pete

Thanks for th reply.

Ah ok, I see...

So if I’m following a course plotted in to the E7d, then the autopilot should automatically change course at each waypoint but that’s about it?

Not sure if it’s worth what will undoubtedly be hassle trying to interface the two just for that

Incidentally, I did try and connect the plotter to the vhf radio in order to get position data on the vhf. Followed instructions but after several hours still couldn’t get it to work so gave up.

Cheers

 

[prv]

So if I’m following a course plotted in to the E7d, then the autopilot should automatically change course at each waypoint but that’s about it?

I doubt that it would automatically make the turns - normally you need to confirm the waypoint advance so that you're not taken by surprise when the boat suddenly makes a major course change, but I don't know how a Cetrek pilot behaves.

What the "track" or "nav" mode is mostly about is ensuring that you follow the planned track over the ground, rather than just keeping the bow of the boat pointed in a particular direction.

It shouldn't be at all difficult to connect, but then the same could be said about the VHF...

Pete

 

[PaulRainbow]

Not really much to add to what Pete has said. The autopilot should steer to a waypoint on the plotter or follow a route, both of which are useful. If you just steer to a compass heading (that's all you can currently do) then you will need to constantly correct the heading to compensate for drift and leeway. If you set the plotter to go to a waypoint, the autopilot will maintain a course over the ground.That's often (but not always) a better method, although you might still want to steer to a compass heading in certain circumstances.

As for connecting, it should simply be a case of connecting two wires, the same as it should be with the VHF. Not having GPS data at the VHF means the DSC functions on the radio are not usable. If you posted the make and model of VHF someone will tell you exactly what wires to connect to where.

 

[Dazzajohm]

Not really much to add to what Pete has said. The autopilot should steer to a waypoint on the plotter or follow a route, both of which are useful. If you just steer to a compass heading (that's all you can currently do) then you will need to constantly correct the heading to compensate for drift and leeway. If you set the plotter to go to a waypoint, the autopilot will maintain a course over the ground.That's often (but not always) a better method, although you might still want to steer to a compass heading in certain circumstances.

As for connecting, it should simply be a case of connecting two wires, the same as it should be with the VHF. Not having GPS data at the VHF means the DSC functions on the radio are not usable. If you posted the make and model of VHF someone will tell you exactly what wires to connect to where.

Thanks for the reply.

Well the VHF is an Icom IC-M323 and as I said I followed the instructions to the letter to get a GPS signal from the E7d but I just couldn’t get it to work.

In relation to this post I believe I only have two NMEA 0183 in/outputs. One is already in use as I have AIS receive plumbed in to the display which incidentally worked fine. So this just leaves one which if it works I can either use for the autopilot in or the gps out... if my understanding is correct.