On Wed, 22 Oct 2003 00:47:45 GMT, "Glen Wiley Wilson"
wrote:


7. To send the GPS signal both to the PC and and the radar, do you
want to split the signal before the PC, or forward the data to the
radar from the PC? Technically, you are supposed to be able to drive
up to 4 NMEA "listeners" from a single NMEA "talker" but I have never
actually done this. You can also buy an NMEA expander which is
designed to drive multiple NMEA circuits, but I think this would be
overkill. Some multiplexors have an NMEA talker port as well as a
serial port, which should work well for you. Don't forget to feed the
autopilot, though.

In the past, NMEA listeners had quite a relatively low input
resistance that loaded the circuitry, rapidly, to peak current
capacity. But, if you put your ohmmeter to the input of the new
devices, you'll find they act almost like an open circuit.

In our "No Computer" configuration on Lionheart, the RS-232 TX output
from the Noland Multiplexer is applied to the master data output
circuit that feeds all the listeners. Noland warned me it was only
capable of 15ma of current, unlike the TLK NMEA outputs which will
sink a lot more. They told me overloading or shorting wouldn't hurt
the Noland multiplexer, it would simply not have sufficient output
levels to key the listeners.

The listeners connected to the master data output a
Icom M602 VHF xcvr
Icom M802 HF-SSB xcvr
Raymarine RL70CRC radar/chartplotter
Garmin 185 GPS/Sonar
B&G Network Pilot autopilot
B&G Yeoman paper chart drafting table
and, at times, a Dell Latitude P4 notebook computer's serial port when
someone forgets to flip the switch to COMPUTER ON.

With all these loads, the 15ma output limit of the Noland multiplexer
runs them all just fine with valid data. Nothing seems unstable.....



Larry W4CSC

3600 planes with transponders are burning 8-10 million
gallons of kerosene per hour over the USA. R-12 car air
conditioners are responsible for the ozone hole, right?

On Tue, 21 Oct 2003 21:17:57 -0400, "Doug Dotson"
wrote:

I have used the Noland and ultimately decided upon the
MiniPlex-41USB from www.shipmodul.com. Far superior
to the Noland in my opinion. If you want a Noland multiplexer
and expander, I'll make you a good deal on them They can
somewhat handle your NMEA and also heat a compartment
as well.

Doug
s/v Callista

Seeing it's a piece of crap, I'll big $20 and be nice......

Want my address? I'll take it......(c;



Larry W4CSC

3600 planes with transponders are burning 8-10 million
gallons of kerosene per hour over the USA. R-12 car air
conditioners are responsible for the ozone hole, right?

On Wed, 22 Oct 2003 09:19:20 +0200, "Meindert Sprang"
tempted fate with:

"Glen Wiley Wilson" wrote in message
news
Again, I would never hook an RS-422 and
an RS-232 circuit together directly. Your mileage may vary.

In general: you can connect a RS-232 output to a NMEA RS-422 input by
connecting teh TX or OUT from the RS-232 to the + or 'A' from an NMEA in,
while connecting the - or B from NMEA in to the ground of teh RS-232 output.
The other way around (RS-422 out to RS-232 in) will mosty not work.

Meindert

Yes, I have seen or done both. I even understand why it works that
way. I was merely stating a policy. When I spec something for
navigating a boat it has to be bulletproof, not a marginal "generally
works" type of thing.

Also, I don't like connecting anything to a ground except another
ground. Seems to me to be asking for several different kinds of
trouble. I am not any kind of an engineer, whereas I believe you are,
but that is my policy. As I said, other peoples's mileage may vary,
but I suspect we are more or less in agreement, or your products would
not be what they are.

On a different subject, do you know what's going on with NMEA2000?
Did it wind up being CAN, and is anyone supporting it yet? It looks
like a sweet deal for the instrument makers. RS-232/CAN convertors
are 3 times the price of RS-422/RS-232 and it looks as if they could
potentially lock out anyone who doesn't pony up the fee to get an ID
assigned. But maybe I'm just paranoid...




__________________________________________________ __________
Glen "Wiley" Wilson usenet1 SPAMNIX at worldwidewiley dot com
To reply, lose the capitals and do the obvious.

Take a look at cpRepeater, my NMEA data integrator, repeater, and
logger at http://www.worldwidewiley.com/

On Wed, 22 Oct 2003 14:02:52 GMT, "Glen Wiley Wilson"
tempted fate with:

On Wed, 22 Oct 2003 09:19:20 +0200, "Meindert Sprang"
tempted fate with:

"Glen Wiley Wilson" wrote in message
news
Again, I would never hook an RS-422 and
an RS-232 circuit together directly. Your mileage may vary.

In general: you can connect a RS-232 output to a NMEA RS-422 input by
connecting teh TX or OUT from the RS-232 to the + or 'A' from an NMEA in,
while connecting the - or B from NMEA in to the ground of teh RS-232 output.
The other way around (RS-422 out to RS-232 in) will mosty not work.

Meindert

Yes, I have seen or done both. I even understand why it works that
way. I was merely stating a policy. When I spec something for
navigating a boat it has to be bulletproof, not a marginal "generally
works" type of thing.

I forgot to mention that NMEA listeners are supposed to be isolated,
so it should be perfectly fine to attach an RS-232 talker to an NMEA
listener. I'm just not sure everyone implemented that particular
feature, given the workmanship I've seen in the instruments I've
cracked open. So, for the record, when speaking for public
consumption, I prefer to play it safe.

But, as I said before, I'm not an expert and I'm willing to be
educated if I'm wrong.

__________________________________________________ __________
Glen "Wiley" Wilson usenet1 SPAMNIX at worldwidewiley dot com
To reply, lose the capitals and do the obvious.

Take a look at cpRepeater, my NMEA data integrator, repeater, and
logger at http://www.worldwidewiley.com/

On Wed, 22 Oct 2003 13:22:48 GMT, (Larry W4CSC)
tempted fate with:



In the past, NMEA listeners had quite a relatively low input
resistance that loaded the circuitry, rapidly, to peak current
capacity. But, if you put your ohmmeter to the input of the new
devices, you'll find they act almost like an open circuit.

In our "No Computer" configuration on Lionheart, the RS-232 TX output
from the Noland Multiplexer is applied to the master data output
circuit that feeds all the listeners. Noland warned me it was only
capable of 15ma of current, unlike the TLK NMEA outputs which will
sink a lot more. They told me overloading or shorting wouldn't hurt
the Noland multiplexer, it would simply not have sufficient output
levels to key the listeners.

The listeners connected to the master data output a
Icom M602 VHF xcvr
Icom M802 HF-SSB xcvr
Raymarine RL70CRC radar/chartplotter
Garmin 185 GPS/Sonar
B&G Network Pilot autopilot
B&G Yeoman paper chart drafting table
and, at times, a Dell Latitude P4 notebook computer's serial port when
someone forgets to flip the switch to COMPUTER ON.

With all these loads, the 15ma output limit of the Noland multiplexer
runs them all just fine with valid data. Nothing seems unstable.....


Interesting. I'd have bet money that would be a flakey setup. You
learn something every day (well you do if you're paying attention.)
If I felt sure that my customers had someone of your expertise aboard,
I might even be comfortable recommending something like that. :-)


__________________________________________________ __________
Glen "Wiley" Wilson usenet1 SPAMNIX at worldwidewiley dot com
To reply, lose the capitals and do the obvious.

Take a look at cpRepeater, my NMEA data integrator, repeater, and
logger at http://www.worldwidewiley.com/

On Wed, 22 Oct 2003 14:26:43 GMT, "Glen Wiley Wilson"
wrote:

Interesting. I'd have bet money that would be a flakey setup. You
learn something every day (well you do if you're paying attention.)
If I felt sure that my customers had someone of your expertise aboard,
I might even be comfortable recommending something like that. :-)

What ****es me off is the manufacturers rarely use a BALANCED feed,
i.e. NMEA + and NMEA - like it calls for. Much cheaper to unbalance
it. The stupid Icom M802 HF-SSB NMEA data input is a GROUNDED BNC RF
connector! That's crazy! Nothing like feeding SSB RF straight from
the radio's cabinet into NMEA - to cause havoc. Of course, if you
hook the coax shield of their connector to SCREEN, instead of NMEA -,
there's no data input to the Icom.....dammit. Idiots.

Garmin has + wire and ground
B&G Network output + wire and ground
Yeoman in and out + wire and ground
Icom M602 VHF in and out + wire and ground

Plenty of room for lots of RF intrusion into the NMEA system and it
all radiates like hell into the HF and VHF from all the stupid
unshielded screw terminals, push terminals, plain wires, unshielded
SeaTalk connectors/wires, it all drives the HF-SSB bands crazy jamming
the receiver with its stupid data noises. The boxes aren't shielded,
either. Garmin's plastic case, Raymarines are all in plastic cases,
B&G's are all in plastic, except for the main computer on the Network
Pilot. The data computer inside the display of Pilot is all plastic
you can see through...unshielded, of course.

Noone seems to care if the data instruments radiate into the radios or
are scrambled by the radios as long as profits are maximized. No
organization forces them to conform to any computer ratings like your
home computer.

It's all nuts.......damned NMEA is gutless to change it.



Larry W4CSC

3600 planes with transponders are burning 8-10 million
gallons of kerosene per hour over the USA. R-12 car air
conditioners are responsible for the ozone hole, right?

"Glen Wiley Wilson" wrote in message
...

On a different subject, do you know what's going on with NMEA2000?
Did it wind up being CAN, and is anyone supporting it yet? It looks
like a sweet deal for the instrument makers. RS-232/CAN convertors
are 3 times the price of RS-422/RS-232 and it looks as if they could
potentially lock out anyone who doesn't pony up the fee to get an ID
assigned. But maybe I'm just paranoid...

Well, it's pretty expensive to get NMEA2000 running for the first product.
All standards, testsuites and manufacter- and product ID for the first
product sets you back for $10,500. So I'll stick to NMEA 0183 for a while
:-)

As far as I see it, only the big guys go for NMEA2000.

Meindert

"Glen Wiley Wilson" wrote in message
...

I forgot to mention that NMEA listeners are supposed to be isolated,
so it should be perfectly fine to attach an RS-232 talker to an NMEA
listener.

That is correct.

I'm just not sure everyone implemented that particular
feature, given the workmanship I've seen in the instruments I've
cracked open. So, for the record, when speaking for public
consumption, I prefer to play it safe.

And that is correct too. Many mfg's have just a single ended input aka 'in'
vs. 'gnd'. Even many with a + and - (differential) you cannot be sure if
they have isolation. Pity that the NMEA organisation does not 'approve'
designs. But rest asu my muxes all have optocouplers inside :-)

Meindert

There was a write up in this month's Ocean Navigator. Thus far only 5
products have been fully certified but another 40 are in the process.
Teleflex has a full line of CANbus engine controls. One thing for sure,
it will be more expensive. The prices for just the cable connectors is
outrageous and no doubt we will end up eating our share of the
certification costs. NMEA charges an arm and a leg for almost
everything they do like that.

Meindert Sprang wrote:

"Glen Wiley Wilson" wrote in message
...

On a different subject, do you know what's going on with NMEA2000?
Did it wind up being CAN, and is anyone supporting it yet? It looks
like a sweet deal for the instrument makers. RS-232/CAN convertors
are 3 times the price of RS-422/RS-232 and it looks as if they could
potentially lock out anyone who doesn't pony up the fee to get an ID
assigned. But maybe I'm just paranoid...


Well, it's pretty expensive to get NMEA2000 running for the first product.
All standards, testsuites and manufacter- and product ID for the first
product sets you back for $10,500. So I'll stick to NMEA 0183 for a while
:-)

As far as I see it, only the big guys go for NMEA2000.

Meindert



--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Did they change the spec? I got ahold of one of the later prelim specs
and just like 0183, they specified no connectors and were pretty solid
on the fact that the flexability of not specifying them was a good thing.

Doug

"Glenn Ashmore" wrote in message
news:TDylb.86906$sp2.60656@lakeread04...
There was a write up in this month's Ocean Navigator. Thus far only 5
products have been fully certified but another 40 are in the process.
Teleflex has a full line of CANbus engine controls. One thing for sure,
it will be more expensive. The prices for just the cable connectors is
outrageous and no doubt we will end up eating our share of the
certification costs. NMEA charges an arm and a leg for almost
everything they do like that.

Meindert Sprang wrote:

"Glen Wiley Wilson" wrote in
message
...

On a different subject, do you know what's going on with NMEA2000?
Did it wind up being CAN, and is anyone supporting it yet? It looks
like a sweet deal for the instrument makers. RS-232/CAN convertors
are 3 times the price of RS-422/RS-232 and it looks as if they could
potentially lock out anyone who doesn't pony up the fee to get an ID
assigned. But maybe I'm just paranoid...


Well, it's pretty expensive to get NMEA2000 running for the first
product.
All standards, testsuites and manufacter- and product ID for the first
product sets you back for $10,500. So I'll stick to NMEA 0183 for a
while
:-)

As far as I see it, only the big guys go for NMEA2000.

Meindert



--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com