"Phil Stanton" wrote in message
...
Does anyone know if there is a depth sounder which shows a negative depth.
OK sounds like a loony question.
I have a lift keel boat and want to set the offset when there is no water
under the keel with the keel down. Same as all sensible people with fixed
keel boats. Easy to do with my Raymarine ST60 Tridata echo sounder. Now if
I
raise the keel to go into shallower waters, there isn't 7 ft (2.2m) of
water
in a lot of places on the East Coast of England, I still want to know how
much water there is underneath me. Hence I need to find an echo sounder
that
shows 0.0m with no water under the keel when down, an say -0.7m when the
depth is 0.7m less than with the keel fully down.
Hence my question. I should have thought with the number of lift keel
boats
there would be a reasonable demand, and lets face it, it isn't rocket
science to make a minus sign show up on a LCD display



Hi Phil,
If that's what you like, it can be done with a Brookhouse NMEA multiplexer.
They do much more than NMEA combining/multiplexing alone. Maybe we should
rename them "NMEA controllers" or something.
One of the functions is NMEA sentence editing "on the fly", i.e. real-time
editing of NMEA parameters, as the sentences pass through the multiplexer.
Editing directives can be uploaded to the multiplexer in setup mode.
http://brookhouseonline.com/pdf%20fi...%20Editing.pdf
We have recently added a new editing directive, for making adjustments to
fields in NMEA sentences, which is ideal for depth offsets, water-speed
correction etc.
The *A directive allows you to add or subtract a signed value from any given
NMEA parameter field of any specified sentence and if the result is
negative, it places a minus-sign in front of it. Of course it re-calculates
the sentence-checksum.
If you connect a repeater instrument to the multiplexer RS422 output and
program it for depth, you'll get exactly what you want, provided you use a
repeater that displays the NMEA field exactly as found in the sentence. You
won't need a new depthsounder. Your ST60 instrument will be suitable as
there is an option for Seatalk to NMEA conversion. Adjust the offset of the
ST60 to display actual water depth and set the "correction" in the
multiplexer to -7.0 and you will get negative depths on the repeater for any
depths under 7 feet.
Wout

Hi Wout

Thanks for the information. I will definitely investigate this further, as
in addition to the depth problem, I am having problems getting my Laptop to
talk to the Autopilot. May be a wiring fault, but apparently the ST60 multi
instrument has NMEA In and Out.
Back to the depth problem. Have you any idea which display instruments will
display a -(minus) sign.
Thanks again for starting me off in the right direction

Phil



"Wout B" wrote in message
...

"Phil Stanton" wrote in message
...
Does anyone know if there is a depth sounder which shows a negative
depth.
OK sounds like a loony question.
I have a lift keel boat and want to set the offset when there is no water
under the keel with the keel down. Same as all sensible people with fixed
keel boats. Easy to do with my Raymarine ST60 Tridata echo sounder. Now
if
I
raise the keel to go into shallower waters, there isn't 7 ft (2.2m) of
water
in a lot of places on the East Coast of England, I still want to know how
much water there is underneath me. Hence I need to find an echo sounder
that
shows 0.0m with no water under the keel when down, an say -0.7m when the
depth is 0.7m less than with the keel fully down.
Hence my question. I should have thought with the number of lift keel
boats
there would be a reasonable demand, and lets face it, it isn't rocket
science to make a minus sign show up on a LCD display



Hi Phil,
If that's what you like, it can be done with a Brookhouse NMEA
multiplexer.
They do much more than NMEA combining/multiplexing alone. Maybe we should
rename them "NMEA controllers" or something.
One of the functions is NMEA sentence editing "on the fly", i.e. real-time
editing of NMEA parameters, as the sentences pass through the multiplexer.
Editing directives can be uploaded to the multiplexer in setup mode.
http://brookhouseonline.com/pdf%20fi...%20Editing.pdf
We have recently added a new editing directive, for making adjustments to
fields in NMEA sentences, which is ideal for depth offsets, water-speed
correction etc.
The *A directive allows you to add or subtract a signed value from any
given
NMEA parameter field of any specified sentence and if the result is
negative, it places a minus-sign in front of it. Of course it
re-calculates
the sentence-checksum.
If you connect a repeater instrument to the multiplexer RS422 output and
program it for depth, you'll get exactly what you want, provided you use a
repeater that displays the NMEA field exactly as found in the sentence.
You
won't need a new depthsounder. Your ST60 instrument will be suitable as
there is an option for Seatalk to NMEA conversion. Adjust the offset of
the
ST60 to display actual water depth and set the "correction" in the
multiplexer to -7.0 and you will get negative depths on the repeater for
any
depths under 7 feet.
Wout

Phil,
Repeaters that can be programmed to display any NMEA data (ASCII
characters), will display whatever is in the depth data field in the DBT
sentence, including the minus sign (put there by the multiplexer, as
explained) The Cruzpro repeater instrument would be a good candidate.
If you already have the ST60 Multi, you can try if it will display a
negative depth by creating a DBT sentence on your laptop with Notepad. Put
e.g. -5.5 in the depth field. Save the sentence in a file. Connect the COM
port of your laptop to NMEA IN of the ST60 instrument (pin 3 to NMEA IN +,
Gnd to NMEA -) and send the .txt file containing the sentence to the
instrument with Hyperterminal (@4800bps, no parity, no flow control). Repeat
this is couple of times and check what the instrument displays. First
configure the instrument for NMEA input, of course.
Wout






"Phil Stanton" wrote in message
...
Hi Wout

Thanks for the information. I will definitely investigate this further, as
in addition to the depth problem, I am having problems getting my Laptop
to
talk to the Autopilot. May be a wiring fault, but apparently the ST60
multi
instrument has NMEA In and Out.
Back to the depth problem. Have you any idea which display instruments
will
display a -(minus) sign.
Thanks again for starting me off in the right direction

Phil



"Wout B" wrote in message
...

"Phil Stanton" wrote in message
...
Does anyone know if there is a depth sounder which shows a negative
depth.
OK sounds like a loony question.
I have a lift keel boat and want to set the offset when there is no
water
under the keel with the keel down. Same as all sensible people with
fixed
keel boats. Easy to do with my Raymarine ST60 Tridata echo sounder. Now
if
I
raise the keel to go into shallower waters, there isn't 7 ft (2.2m) of
water
in a lot of places on the East Coast of England, I still want to know
how
much water there is underneath me. Hence I need to find an echo sounder
that
shows 0.0m with no water under the keel when down, an say -0.7m when
the
depth is 0.7m less than with the keel fully down.
Hence my question. I should have thought with the number of lift keel
boats
there would be a reasonable demand, and lets face it, it isn't rocket
science to make a minus sign show up on a LCD display



Hi Phil,
If that's what you like, it can be done with a Brookhouse NMEA
multiplexer.
They do much more than NMEA combining/multiplexing alone. Maybe we
should
rename them "NMEA controllers" or something.
One of the functions is NMEA sentence editing "on the fly", i.e.
real-time
editing of NMEA parameters, as the sentences pass through the
multiplexer.
Editing directives can be uploaded to the multiplexer in setup mode.
http://brookhouseonline.com/pdf%20fi...%20Editing.pdf
We have recently added a new editing directive, for making adjustments
to
fields in NMEA sentences, which is ideal for depth offsets, water-speed
correction etc.
The *A directive allows you to add or subtract a signed value from any
given
NMEA parameter field of any specified sentence and if the result is
negative, it places a minus-sign in front of it. Of course it
re-calculates
the sentence-checksum.
If you connect a repeater instrument to the multiplexer RS422 output and
program it for depth, you'll get exactly what you want, provided you use
a
repeater that displays the NMEA field exactly as found in the sentence.
You
won't need a new depthsounder. Your ST60 instrument will be suitable as
there is an option for Seatalk to NMEA conversion. Adjust the offset of
the
ST60 to display actual water depth and set the "correction" in the
multiplexer to -7.0 and you will get negative depths on the repeater for
any
depths under 7 feet.
Wout

Phil Stanton wrote:
Hi Wout

Thanks for the information. I will definitely investigate this further, as
in addition to the depth problem, I am having problems getting my Laptop to
talk to the Autopilot. May be a wiring fault, but apparently the ST60 multi
instrument has NMEA In and Out.

A good way to trouble shoot NMEA data problems is to use the
Hyperterminal communications utility included with Windows. That will
show you the NMEA data flow as scrolling ascii text strings. And the
strings can even be saved to a text file for later study.

To use it, select the COM port your NMEA data is on in the "Connect
using:" box. Then change the settings to 4800 baud, 8 data bits, parity
to none, and stop bits to 1. If your NMEA data is at a different baud
rate you may have to change that, the display will be repeated garbles
when that happens. Sometimes you can check the setup on your NMEA
talkers to see what baud rate is being used, they all need to be the same.

Seeing the NMEA data strings tells you your laptop setup is working and
can help you isolate the problem.

There is a known problem with Windows misidentifying a GPS or NMEA input
as a serial mouse. If you go to the device manager find a serial mouse
there, disable it and leave it disabled and that will not happen again.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

Sorry for delay in replying. Couldn't check it out till the weekend. Bags of
input from a GPS to the HyperTerminal, but nothing from the ST60 Multi. I
think it could be faulty

Thanks for steering me towards the HyperTerminal. I had never heard of it.

Phil


"Jack Erbes" wrote in message
...
Phil Stanton wrote:
Hi Wout

Thanks for the information. I will definitely investigate this further,
as in addition to the depth problem, I am having problems getting my
Laptop to talk to the Autopilot. May be a wiring fault, but apparently
the ST60 multi instrument has NMEA In and Out.

A good way to trouble shoot NMEA data problems is to use the Hyperterminal
communications utility included with Windows. That will show you the NMEA
data flow as scrolling ascii text strings. And the strings can even be
saved to a text file for later study.

To use it, select the COM port your NMEA data is on in the "Connect
using:" box. Then change the settings to 4800 baud, 8 data bits, parity
to none, and stop bits to 1. If your NMEA data is at a different baud
rate you may have to change that, the display will be repeated garbles
when that happens. Sometimes you can check the setup on your NMEA talkers
to see what baud rate is being used, they all need to be the same.

Seeing the NMEA data strings tells you your laptop setup is working and
can help you isolate the problem.

There is a known problem with Windows misidentifying a GPS or NMEA input
as a serial mouse. If you go to the device manager find a serial mouse
there, disable it and leave it disabled and that will not happen again.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

Phil Stanton wrote:
Sorry for delay in replying. Couldn't check it out till the weekend. Bags of
input from a GPS to the HyperTerminal, but nothing from the ST60 Multi. I
think it could be faulty

Thanks for steering me towards the HyperTerminal. I had never heard of it.


You're welcome. Its been a freebie with Windows as long as I can
remember, great to use as a console for talking to various devices like
switches and routers, good for testing modems, and trouble shooting some
other devices.

As an added note, someone on another group pointed out to me that
Hyperterminal will not always work as I described it. It will work for
receive only connections but if the sending device expects that there
will two way communications it will not or may not work. I'm not that
smart about RS-232 communications and can't further explain that but it
sounds reasonable to me. Nothing else in Windows is guaranteed to
always work, why should that? :)

But it has been a good trouble shooting tool for me in checking out GPS
to PC connections.

Do you know that your ST-60 is communicating in a RS-232 serial mode?
If that is a SeaTalk instrument or in that mode, it won't work because
that is Raymarine's proprietary flavor of RS-232 or something like that.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

Hi Jack

There doesn't seem to be a way of specifically setting the ST60 to output in
RS-232 serial mode. In addition to the SeaTalk connections on the back of
the instrument there are 2 pairs of connections marked NMEA Out and NMEA In.
In addition there is a setting on the instrument for "NMEA Output ON". It
all sounds terribly logical..
Have contacted RayMarine and wait their opinion.

Thanks

Phil

"Jack Erbes" wrote in message
...
Phil Stanton wrote:
Sorry for delay in replying. Couldn't check it out till the weekend. Bags
of input from a GPS to the HyperTerminal, but nothing from the ST60
Multi. I think it could be faulty

Thanks for steering me towards the HyperTerminal. I had never heard of
it.


You're welcome. Its been a freebie with Windows as long as I can
remember, great to use as a console for talking to various devices like
switches and routers, good for testing modems, and trouble shooting some
other devices.

As an added note, someone on another group pointed out to me that
Hyperterminal will not always work as I described it. It will work for
receive only connections but if the sending device expects that there will
two way communications it will not or may not work. I'm not that smart
about RS-232 communications and can't further explain that but it sounds
reasonable to me. Nothing else in Windows is guaranteed to always work,
why should that? :)

But it has been a good trouble shooting tool for me in checking out GPS to
PC connections.

Do you know that your ST-60 is communicating in a RS-232 serial mode? If
that is a SeaTalk instrument or in that mode, it won't work because that
is Raymarine's proprietary flavor of RS-232 or something like that.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

Phil Stanton wrote:

Hi Jack

There doesn't seem to be a way of specifically setting the ST60 to output in
RS-232 serial mode. In addition to the SeaTalk connections on the back of
the instrument there are 2 pairs of connections marked NMEA Out and NMEA In.
In addition there is a setting on the instrument for "NMEA Output ON". It
all sounds terribly logical..
Have contacted RayMarine and wait their opinion.


Sounds like you're using the right connections then. NMEA is RS-232 by
definition. The ST-60 NMEA Out and NMEA In would normally be connected
to the RS-232 RXD and TXD. If you have not tried it, reversing the
connections is worth a try. The connections are made so that the NMEA
output goes to a RS-232 input and the NMEA input comes from an RS-232
output giving you the following:

NMEA Out --- RS-232 RXD
NMEA In --- RS-232 OUT

Various terms are used for the connections, the semantics can be
confusing, and human error can rear its head. So swapping the two leads
has become a routine step in trouble shooting for me.

A final thing. If one of the devices has connections for both a
"Ground" and for "Power (-)", sometimes connecting those two together
will make it work. You can test that with a temporary jumper.

An example of that was the wiring for a cable I made for NMEA serial
connection between my iPAQ 3675 and Magellan 330M. It simply would not
work until the shield on the 330M cable and lead called "Ground" on the
3675 were connected to the negative power lead.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

"Phil Stanton" wrote in message
...
Hi Jack

There doesn't seem to be a way of specifically setting the ST60 to output
in
RS-232 serial mode. In addition to the SeaTalk connections on the back of
the instrument there are 2 pairs of connections marked NMEA Out and NMEA
In.
In addition there is a setting on the instrument for "NMEA Output ON". It
all sounds terribly logical..
Have contacted RayMarine and wait their opinion.

Thanks

Phil

"Jack Erbes" wrote in message
...
Phil Stanton wrote:
Sorry for delay in replying. Couldn't check it out till the weekend.
Bags
of input from a GPS to the HyperTerminal, but nothing from the ST60
Multi. I think it could be faulty

Thanks for steering me towards the HyperTerminal. I had never heard of
it.


You're welcome. Its been a freebie with Windows as long as I can
remember, great to use as a console for talking to various devices like
switches and routers, good for testing modems, and trouble shooting some
other devices.

As an added note, someone on another group pointed out to me that
Hyperterminal will not always work as I described it. It will work for
receive only connections but if the sending device expects that there
will
two way communications it will not or may not work. I'm not that smart
about RS-232 communications and can't further explain that but it sounds
reasonable to me. Nothing else in Windows is guaranteed to always work,
why should that? :)

But it has been a good trouble shooting tool for me in checking out GPS
to
PC connections.

Do you know that your ST-60 is communicating in a RS-232 serial mode? If
that is a SeaTalk instrument or in that mode, it won't work because that
is Raymarine's proprietary flavor of RS-232 or something like that.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)


Hi,
I was under the impression that the whole exercise was to determine if the
ST60 Multi instrument would display a negative depth if received in a NMEA
depth sentence.
For this test, you want to connect the Transmit line of the PC Com port to
NMEA IN. Connect your PC Com port pins 3 and 5 to NMEA IN + and NMEA IN -
and transmit a $SDDBT sentence from Hyperterminal to the ST60 Multi
instrument.
Start Windows program Notebook and type the following NMEA sentence:
$SDDBT,-2.0,f,,,,*22 Press Enter and save this text in a file. The
value -2.0 represents a "negative" depth of 2.0 feet.
Start Hyperterminal with the PC connected to the ST60 instrument as
described above. Click on Transfer at the top of the Hyperterminal screen
and select "Send Text File". Find the .txt file you saved with Notebook and
transmit. Repeat this a few times and it will become clear if the ST60 Multi
is willing to display a negative value. Try a positive depth first to check
if you've got the connections right, e.g. $SDDBT,3.0,f,0.9,M,0.5,F*09

Wout

Jack Erbes wrote in news:mPidnfR-_vQresTfRVn-
:

As an added note, someone on another group pointed out to me that
Hyperterminal will not always work as I described it. It will work for
receive only connections but if the sending device expects that there
will two way communications it will not or may not work. I'm not that
smart about RS-232 communications and can't further explain that but it
sounds reasonable to me. Nothing else in Windows is guaranteed to
always work, why should that? :)


Those problems are usually because of the hardware connections associated
with CTS (clear to send) and RTS (request to send) lines not being held
high. RS-232 is made for hardware handshaking between devices so the
listening device can stop the transmission when its buffer (bit bucket?) is
full. It goes way back to really dumb terminals that have no storage in
them for data. Jumpers added to the DB9 or DB25 connectors can make it run
wide open to hyperterm on dumb data....er, ah, like NMEA..(c;

http://www.aggsoft.com/rs232-pinout-...and-signal.htm

http://www.aggsoft.com/rs232-pinout-cable/
Aggsoft has a serial port monitor and a data logger you can download and
try for free....

http://www.connectworld.net/rs232.html

And, for you boys and girls, Mr Rogers has a website:
http://www.routergod.com/misterrogers/

The other problem is Com1 and 3 use IRQ 4 interrupt while Com2 and 4 use
IRQ 3 interrupt. If the Com1 serial mouse is attached, putting your data
on Com 3 will make it all go crazy.
http://www.bbdsoft.com/rs232.html

http://www.zytrax.com/tech/layer_1/c...tech_rs232.htm