SeaTalk1 <-> NMEA Bridge Installation and Operation Manual Version : Bridge128SD Software Version 3.01 June 2013 1 SeaTalk is Reg. Trademark of Raymarine Inc. © 2013 All Rights Reserved © 2013 Alle Rechte vorbehalten Hw Version 128-1.0 / Sw Version 3.01 Page 1 of 28 http://www.gadgetPool.de FWallenwein@gadgetPool.
Credits / Warning / Disclaimer The protocol converter is a RESEARCH PROJECT It is used for research on data communication, computer communication and data conversion on computers used on board boats. Hard- and Software are still under development and have NOT been fully tested. Malfunctions of the protocol converter and of any connected device are possible at any time. The protocol converter could cause damage to connected devices.
SeaTalk <-> NMEA Bridge Contents CREDITS / WARNING / DISCLAIMER 2 OVERVIEW 4 CONNECTIONS 5 POWER SUPPLY SEATALK CONNECTION NMEA CONNECTION RS232 CONNECTION USB PC PORT 5 5 6 7 8 DISPLAY AND KEYS 9 DISPLAY KEY FUNCTIONS : INSTALLATION AND COMMISSIONING MOUNTING USB DRIVER INSTALLATION USB COM PORT ASSIGNMENT NMEA INPUT- AND OUTPUT PORT SELECTION CONNECTION EXAMPLES DATA FLOW NMEA INPUT NMEA OUTPUT SEATALK INPUT SEATALK OUTPUT SAME TYPE OF DATA ON NMEA & SEATALK SPECIAL FUNCTIONS AND CONFIGURATION
SeaTalk <-> NMEA Bridge Overview The converter interconnects two different data communication systems – SeaTalk 2 and NMEA 0183. Information from the SeaTalk network is transformed into NMEA Data and sent to the NMEA ports. Information from the NMEA ports is transformed into SeaTalk data and sent to the SeaTalk bus. SeaTalk and NMEA data are shown on a LCD display.
SeaTalk <-> NMEA Bridge Connections Power Supply The bridge takes it’s power supply from +12V and GND. 12 Volt DC power supply (e.g. from battery) must be protected with a 1 amp circuit breaker or fuse. The bridge consumes approx 60 mA in idle mode, 50 mA when backlight is switched off and can consume temporarily up to 100 mA when sending data. GND +12 Volt SeaTalk connection +12 Volt Red SeaTalk Data Yellow GND Silver A 3-Pin terminal is used for the connection to the SeaTalk bus.
SeaTalk <-> NMEA Bridge NMEA Connection The board has 1 * NMEA-IN3 1 * NMEA-OUT port. The NMEA-IN port is used to receive data from standard NMEA devices like GPS etc. This standard NMEA devices usually have terminals marked with NMEA OUT+, NMEA OUT-. ( On some devices the ports are marked NMEA-OUT-A, NMEA-OUT-B ) NMEA-OUT - NMEA-OUT + NMEA-IN + NMEA-IN - The NMEA-OUT port is used to send data to standard NMEA devices like GPS, VHF etc.
SeaTalk <-> NMEA Bridge RS232 Connection The board has 1 * RS232 port for reading4 and writing NMEA data The RS232 port is used to send and receive data to/from a standard NMEA device that has an RS232 port instead of a NMEA port. Many GPS devices, i.e. hand-held GPS, have RS232 ports instead of NMEA ports. The RS232 port can also be used to connect the bridge to a computer that only has a serial port but no USB port. TxD RxD GND 4 IN-port can be switched between NMEA-IN and RS232 RxD.
SeaTalk <-> NMEA Bridge USB PC Port The board has 1 * USB port for PC connection. The USB Port speed is currently fixed to 4800 Baud. The bridge has one USB port. It can be used to connect it to a computer or notebook. After connection the bridge, a new serial port will be available on your computer ( See Page 12 – Com Port assignment ) With this serial port, the computer can act as a NMEA sender and as a NMEA receiver.
SeaTalk <-> NMEA Bridge Display and Keys The SeaTalk NMEA bridge has a 4 * 20 character display and 7 push buttons. Display The display shows SeaTalk and NMEA data. It has 4 pages, selectable by Key-1 to Key-4 or by Key-Up and Key-Down Page 1 Speed t. water Depth Position Position over ground Temperature Course true Course magnetic Page 2 Wind speed Wind direction Course magnetic Course true Trip mileage Total mileage UTC Time Page 3 Waypoint data From WP Name XTE Distance Speed t.
SeaTalk <-> NMEA Bridge Key functions : Key Function Key 1 Key 2 Key 3 Key 4 Select display page 1 Select display page 2 Select display page 3 Select display page 4 Key Down Select next display page Key Up Select previous display page Key Enter Display illumination on/off Key Enter pressed Configuration menu for 5 seconds Key Down pressed NMEA & RS232 loopback test for 5 seconds SeaTalk NMEA Bridge 128SD Sw Version 3.
SeaTalk <-> NMEA Bridge Installation and commissioning Mounting Before starting the installation, you should take some time to find the best position for the instrument. Of course it should be placed so that the display is easily readable and the push buttons are easily accessible. It must be placed in a dry and ventilated place. Make sure that there is enough space behind the instrument to accommodate the instrument connectors and cables.
SeaTalk <-> NMEA Bridge USB Driver installation Depending on the operating system of the computer, it might be necessary to install a driver software. The bridge is using a standard FTDI USB serial converter chip. Drivers for this chip can be found on the CD and on the FTDI webpages. (http://www.ftdichip.com/FTDrivers.htm) Linux A reasonable modern LINUX system does not need a special driver installation. The FTDI chip will be recognized and the system will provide a new serial port.
SeaTalk <-> NMEA Bridge NMEA Input- and Output Port selection All OUT-ports are always enabled : The Out-ports - NMEA-OUT, RS232 TxD and USB - are always enabled. The SeaTalk NMEA bridge always sends data to the NMEA-OUT port, the RS232 TxD pin and to the USB port. You can - for example - send data from the SeaTalk NMEA bridge to a Computer (USB) and a GMDSS radio (NMEA-OUT) at the same time. The IN-port is selectable : The bridge can receive NMEA data from either NMEA-IN or from RS232 RxD pin.
SeaTalk <-> NMEA Bridge Data Flow SeaTalk Device Seatalk<-> NMEA Bridge NMEA OUT PORT OUT+ IN- SeaTalk NMEA IN PORT OUT- IN- IN+ IN+ OUT- OUT+ NMEA-DEVICE Receiver i.e. GMDSS Radio NMEA-DEVICE Transmitter USB USB Port Computer RS232 TxD RxD GND RxD TxD GND RS232 Device ( PC, GPS ...) i.e. GPS Received SeaTalk data are translated into NMEA and sent to NMEA-OUT port and to the RS232 TxD pin and to the USB port.
SeaTalk <-> NMEA Bridge NMEA Input NMEA sentences can be received from the NMEA-IN or RS232 port and from the USB port. Processing of NMEA data starts, when a complete NMEA sentence has been received. If the received sentence contains a checksum, this checksum is used to check for communication errors. If the checksum does not match the sentence, the received NMEA sentence is discarded. If the sentence does not contain a checksum, the sentence is always regarded as valid.
SeaTalk <-> NMEA Bridge NMEA Output All valid NMEA sentences – whether processed by the converter or not – are forwarded to the NMEA-OUT port and to the USB Port. If the NMEA-OUT port is busy, the sentence is temporarily stored in memory and transmitted as soon as the NMEA-OUT port becomes free. NMEA input SeaTalk input USB + (NMEA-IN or RS232 RxD) The converter also continuously checks for new incoming SeaTalk data.
SeaTalk <-> NMEA Bridge SeaTalk Input When a SeaTalk datagram was received, the system checks if this datagram is known and should be processed. When the datagram is known, the datagram parameters are extracted, stored and converted to an NMEA sentence. Any unknown datagram is ignored. ( Exception: $STALK is sent even for unknown datagrams ) At this time the following SeaTalk datagrams can be received.
SeaTalk <-> NMEA Bridge SeaTalk Output The converter periodically checks if any new data has arrived from one of the NMEA- or the USB port. Newly arrived data are converted to SeaTalk and written to the SeaTalk. The bridge checks if the SeaTalk bus is free, or it is currently used by any other instrument. If the bus is in use, the converter waits for a while, and tries again. Collision detection Every single bit sent out to the SeaTalk bus is read back again and checked for successful transmission.
SeaTalk <-> NMEA Bridge Special functions and configuration Configuration screen The SeaTalk NMEA converter can be configured to meet the users requirements. The settings are stored in an internal EEProm. The configuration can be set in the configuration screen. → To enter the configuration screen, press key ENTER for 5 seconds.
SeaTalk <-> NMEA Bridge Configuration example Example 1: In this example we configure the bridge, so that the NMEA baudrate is changed to 38400 baud. – – – – Find function ID for baudrate in table on page 22. Function ID for baudrate is 1 Find value for 38400 baud in table on page 22.
SeaTalk <-> NMEA Bridge Configuration commands The SeaTalk NMEA converter can be configured to meet the users requirements. The configuration is made by sending a NMEA-like sentence. The settings are stored in an EEProm. The configuration sentence is : $SNBSE,address,data ( Optionally a checksum can be appended $SNBSE,address,data*XX) ( SNBSE = SeaTalk NMEA Bridge Set Eeprom ) Configuration settings a read, when the bridge gets switched on.
SeaTalk <-> NMEA Bridge Configuration Id's Function Value ID 0 1 = Send out every incoming SeaTalk datagram as "$STALK....." to NMEA 0 = Do not generate $STALK,xx,yy sentence for each incoming SeaTalk datagram If you don’t really need this function – better switch if OFF. It causes additional load on the NMEA Bus.
SeaTalk <-> NMEA Bridge 13 14 15 16 17 18 19 20 21 22 23+24 25 26 27 28 29 30 31 32 33 34 35 1 = Send welcome message after power up 0 = Do not send welcome message 0 = Speed over ground from NMEA input is sent to SeaTalk as speed over Ground and as speed through water ( Needed for ST60 Wind instrument, that does not recognize speed over ground ) 1 = Normal operation. No special SOG => STW handling ) ( default ) ( See Webpage www.gadgetPool.de for more on this special ST60 Wind function.
SeaTalk <-> NMEA Bridge Special NMEA like commands The $STALK sentence The converter can process a special NMEA-like sentence. With this special sentence any SeaTalk command can be sent to SeaTalk. $STALK,cc,p1,p2..,pn*xx cc = SeaTalk command p1 = Parameter 1 p2 = Parameter 2 .. *xx = NMEA checksum ( optional ) . Example : Switch on display illumination on all devices on the SeaTalk network. Enter $STALK,30,00,0C Switch off display illumination on all devices on the SeaTalk network.
SeaTalk <-> NMEA Bridge Software update The board software can be updated by using the built in Bootstrap-Loader function. If you find anything missing in the software, if you should find any software errors or if you have new ideas – just sent a mail to FWallenwein@tklinux.de New / revised software can be sent by E-Mail and the SeaTalk NMEA bridge owner can update the controller software him/herself. Bootstrap method advantages : No hardware programmer needed.
SeaTalk <-> NMEA Bridge SeaTalk & NMEA conversion Table Function Depth SeaTalk ID NMEA 0 DBT Stalk -> NMEA X NMEA->Stalk X X Speed t. water 20 VHW X Speed t.
SeaTalk <-> NMEA Bridge Technical data Instrument Width Height Depth Weight : : : : Clearance hole Width Height : : 141.5 mm 75.0 mm 37.5 mm 165.0 grams 104 mm 66 mm Minimum cable clearance behind panel : 40 mm Supply voltage Current consumption : 8 to 30 Volt DC : 60 mA idle, 50 mA backlighting off, 100 mA peak (12 Volt) News and Info on the web. If you have any question or suggestions – there is a SeaTalk NMEA bridge user forum on our web page. http://www.gadgetPool.
SeaTalk <-> NMEA Bridge ASCII Table Upper case letters Character A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Lower case letters a b c ……………….. x y z Digits 0 1 2 3 4 5 ASCII Value 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 97 98 99 120 121 122 48 49 50 51 52 53 SeaTalk NMEA Bridge 128SD Sw Version 3.
