Multiple nmea 0183 inputs

[Hoghead]

I am trying to install a Ray eS127 MFD and stuck on how to connect multiple NMEA 0183 inputs

I have an AIS with either RS-232 or RS-422 outputs, that I am trying to figure out how to connect to NMEA 0183 and the subject of a different thread.

I also have a AP 26 Simrad pilot with AC20 computer that has NMEA 0183 only.
Or I think that it is 0183 only as I see no other connections on the AC20 terminal board, even though the manual mentions NMEA 2000?
I have a question into Simrad and holding my breath for an answer that is very slow in forthcoming

The Ray has only 1 NMEA 0183 input, plus 1 NMEA 2000

How to connect 2 NMEA 0183 devices, at least one of which of which will be high speed?
Or do I need to buy a MUX?

Ideally I could connect the pilot and AIS to the NMEA 2000 bus but this does not seem, at this point at least, an option.

[Paul Elliott]

Originally Posted by Hoghead

Or do I need to buy a MUX?

I think so. NMEA0183 outputs can not be connected together. Each output needs to go to a separate input. A MUX can take multiple inputs, combine them (and in some cases do some useful manipulation of the input data), and then send the combined data to the NMEA0183 input of another device.

And yes, if you have N2K devices, they can usually be connected together without needing a MUX.

[Hoghead]

Originally Posted by Paul Elliott

I think so. NMEA0183 outputs can not be connected together. Each output needs to go to a separate input..

That is what I thought but re-reading the Ray eS127 MFD manual it says that there are 2 NMEA 0183 inputs in the combined power/data cable

Port 1 is in and out using 4 wires using 2 wires,
and somehow can take 4 devices

Port 2 is in only and can take 2 devices

More confused than ever

[smac999]

connect port 2 input to AIS output. set to 38,400 in plotter 2 wires

port 1 connect input and output to pilot. so you get gps to pilot and heading to plotter. set to 4800. 4 wires.

each input can only take one device.

[CarinaPDX]

The "taking 4 devices" refers to how many listening devices can be connected to one talker. NMEA 0183 devices should be able to output enough to drive 4 inputs, but that is not always the case - particularly with older devices. As covered earlier, an input ("listener") can only listen to a single talker (device).

Greg

[CarinaPDX]

@Hoghead: It is considered bad form to open multiple threads on the same topic. What do you hope to accomplish? Properly, you should ask a moderator to combine the two threads and continue from there.

I suspect your confusion starts with not knowing where you are going. What are you trying to accomplish? If you want to display AIS data on the RM MFD then you need one pair of wires from the AIS output to the MFD input. If you want to feed the autopilot (AP) with waypoint and/or cross-track (XTE) data from the MFD then you need to connect a pair of wires from an MFD output to one of the AC20 inputs. You will probably want the AP to output compass heading info to the MFD, so you will need a second pair of wires from the AC20 out to the MFD in. So, use the NMEA2 TX/RX pairs on the AC20's TB10 (terminal block 10) to the MFD's NMEA port 1 RX/TX pairs. And as covered on the other thread, the AIS NMEA out to the MFD's Port 2 input. Is that not clear? If not then get someone else to do the job.

Greg

[Hoghead]

Originally Posted by CarinaPDX

@Hoghead: It is considered bad form to open multiple threads on the same topic. What do you hope to accomplish? Properly, you should ask a moderator to combine the two threads and continue from there.

I suspect your confusion starts with not knowing where you are going. What are you trying to accomplish? If you want to display AIS data on the RM MFD then you need one pair of wires from the AIS output to the MFD input. If you want to feed the autopilot (AP) with waypoint and/or cross-track (XTE) data from the MFD then you need to connect a pair of wires from an MFD output to one of the AC20 inputs. You will probably want the AP to output compass heading info to the MFD, so you will need a second pair of wires from the AC20 out to the MFD in. So, use the NMEA2 TX/RX pairs on the AC20's TB10 (terminal block 10) to the MFD's NMEA port 1 RX/TX pairs. And as covered on the other thread, the AIS NMEA out to the MFD's Port 2 input. Is that not clear? If not then get someone else to do the job.

Greg

This thread is about multiple 0183 devices into one input and stemming from Raymarine eS127 manual terminology suggesting that a single input can accept either 2 or 4 devices.
My other thread while related, did not raise this point

I am in the Philippines where technical support is non-existent. If there was someone that could do this for me I would have done that a week ago.

Your comments however have been very helpful and I now understand how to wire the pilot.

[Paul L]

Think of NMEA183 connection as Single Talker, Multiple Listener.