NBF-1 User Manual Issue 1.30
Contents
1. a typical installation with both fully compliant NMEA devices with differential outputs and non differential devices that output NMEA using the ground line as the NMEA line Please note that only one NMEA device can be connected to NMEA IN at any one time NMEA Talker device A This device conforms in full to the NMEA 0183 standard and shares the same connection ID s as the Actisense NBF so connection is a Simple matter of matching ID s refer to figure 2 NMEA Talker device B This is a single ended non differential device and does not conform completely to the NMEA 0183 standard However by connecting to A and its G Ground to the NBF B the NBF should be able to receive the NMEA data correctly 2005 Active Research Limited Personal Computer A PC s RS232 output may be directly connected to the NBF allowing a PC to drive many NMEA instruments from its RS232 port without risk of damage or overload Simply connect the PC s Tx pin Pin 3 on 9 pin D type connector to the NBF s A and its Ground Pin 5 on D type to the B Connecting to the battery supply The Actisense NBF 1 should be wired to the vessel s battery supply in the most direct manner possible to minimize interference from other electronic devices The cable used should be of sufficient gauge to handle the power requirements of the Actisense NBF 1 refer to the Specifications se2. also requires that all receiving equipment must be Opto isolated this Opto isolation requirement reduces the chances of interference and removes the problem of ground loop effects Technical features The NMEA 0183 input is a full galvanic opto isolated differential input to fully comply with the NMEA 0183 standard specification This allows the input to work correctly with long cable runs and in a noisy environment Typical operating voltage is 2 0v to 15 0v The unit can withstand 35v continuously and 40v transients The Opto isolator can protect any upstream equipment chart plotter laptop PC radar etc from up to 2000v of common mode voltage difference Removes all problematic ground loops between the NMEA device connected to the NBF 1 input port and all the NMEA devices connected to the output ports 4 NMEA 0183 full differential output drivers These outputs can drive up to 16 fully compliant NMEA 0183 device loads with a 32 mA maximum drive capability In practice due to a lack of NMEA compliancy this can reduce the maximum drive capability down to 8 NMEA devices The full differential output ensures better quality communications and lower noise emissions on unshielded twisted pair cabling 2005 Active Research Limited 2 NMEA 0183 RS232 data output drivers These outputs have a typical drive capability of 2 NMEA devices each They offer extra compatibility with older NMEA instruments and standard compute
3. specialist consultancy and customisation E mail support activer com Website www activer com 2005 Active Research Limited Page 12
4. Actisense NMEA Buffer NBF 1 B User Manual Issue 1 30 a Galvanically Opto isolated NMEA 0183 data input for complete isolation between input and outputs a 4 NMEA 0183 RS422 RS485 data standard outputs capable of driving at least 8 NMEA 0183 instruments each a 2 NMEA 0183 RS232 data outputs for compatibility with new and old NMEA instruments and computer RS232 ports NMEA Buffer NBF 1 B Contents Important Notices Notices Foreword Introduction NMEA 0183 Introduction Electrical specifications Technical features Connecting devices together The basics The NMEA signals The different NMEA standards Connections Input Connections NMEA 0183 Input Connecting to the battery supply Output Connections NMEA 0183 RS422 Outputs NMEA 0183 RS232 Outputs Troubleshooting guide Specifications Company Information o o O oo ON oooO iu Ji bh A A A A nN 2005 Active Research Limited Page 3 Actisense Important Notices The Actisense NMEA Data Combiner NBF 1 is intended for use in a marine environment primarily for below deck use If the unit is to be used in a more severe environment such use may be considered misuse under the seller s warranty The Actisense NMEA Buffer NBF 1 has been certified to comply with the European directive for Electro Magnetic Compatibility EN60945 and is appropriately CE marked Operation of the unit should be in conjunction with appropr
5. Neither the NMEA sentence checksum nor the data contained within the NMEA sentence is validated Therefore the electronic device s supplying the NBF 1 with NMEA data retain s the sole responsibility for the NMEA data s validity 2005 Active Research Limited Foreword Actisense recognises that instructions are often skipped so we have aimed to write this document in an informative yet direct manner that will aid the user We have tried to cover all the points a typical user may need to know Please read all sections before installing and using the Actisense NMEA Buffer product and any related software programs Introduction The Actisense NMEA Buffer NBF 1 product was developed to solve a common problem wanting to share the NMEA information from an NMEA device with more than two other NMEA instruments Most NMEA output s e g GPS can only drive 1 or 2 NMEA devices any more and the signal becomes degraded and corruption of the NMEA data occurs The Actisense NMEA Buffer solves all NMEA buffering problems by allowing distributed buffering of one NMEA instrument s data output to a large number of other NMEA device inputs and if required even a PC s RS232 port Utilising fourteen years of experience in the marine industry in creating market leading depth sounders and other NMEA products Actisense recognised the need to produce a full galvanic Opto isolated dependable NMEA buffering solution that meet
6. cepted Page 5 Actisense Connecting devices together The basics NMEA data is transmitted from an information source such as GPS depth sounder gyro compass etc These data sending devices are called Talkers Equipment receiving this information such as a chart plotter radar or NMEA display is called a Listener Unfortunately only one Talker can be connected on to a single NMEA 0183 system at any one time Two or more Talkers are simply not possible because they are not synchronised to each other and will attempt to talk at the same time over each other resulting in corruption of the NMEA data and potentially in disaster if valuable data such as navigation information is lost or corrupted so that it is incorrect and or misleading This fundamental problem with the NMEA system can be easily overcome and multiple Talkers connected together using the Actisense NMEA Data Combiner Multiplexer NDC 2 and NDC 3 If the required system has multiple NMEA Talker device of the same type e g two GPS units the highest priority device can be automatically switched using the Actisense Autoswitch NSW 1 Please visit the Actisense website for full details on these and other Actisense products The output drive capability of many instruments means that often their NMEA outputs can only drive one or two Listeners In this case the output of the Talker can be boosted to talk to a typica
7. corruption errors may occur Please refer to the Output Connections section for example of these connection methods Page 6 www ac t QO yOG B81Z0850 JSNISILIV ACTIVE hanai LTD 2005 isense com o oe mls LE je oe NMEA Buffer NBF 1 B Connections wv sai a m C U aN elu gt 0 2 Z N a a lt U NMEA BUFFER QO 99999 AUOT NBF 1 Figure 1 All external connections An NMEA 0183 input The NMEA 0183 input is of the differential opto isolated type and uses the unique Actisense low current drain circuitry 2mA 2 0v to conform in full with the NMEA 0183 marine electronic device network communication standard and is flexible enough to interface to most full and partially compliant devices 4 NMEA 0183 RS422 outputs Each NMEA 0183 RS422 output comprises of two connections A and B and conforms in full to the NMEA 0183 standard 2 NMEA 0183 RS232 outputs Each NMEA 0183 RS232 output comprises of two connections Tx and GND and conforms in full to the NMEA 0183 standard Battery supply input 2005 Active Research Limited The NMEA Buffer NBF 1 has screw terminal Phoenix type external connections for Note 1 To complete the NMEA 0183 standard all device interconnection NMEA cables used should meet the two conductor shielded twisted pair configuration specification The shield conn
8. ctions Note 1 Wire colours are for guidance only Page 8 NMEA Buffer NBF 1 B Output Connections ACTIVE D LTD 2005 www ac t Personal Rx isense com pH o E man co NMEA peHo ue Computer G fi og Ms IMER casa ae aena er wez Listener 5 ae cm 7g ae Me e Listener 3 swan Z mp L NMEA aoa 6 ET a IE A u Listener 2 ro0 81cOSA J NMEA A Listener 7 B San EOR A Te Fi oe MeH NMEA Listener 1 NMEA BUFFER Figure 3 Output connections NMEA 0183 RS422 Outputs The NMEA 0183 RS422 buffered outputs are capable of driving up to 16 fully NMEA 0183 compliant listening devices each In practice however this can be reduced down to 8 listening devices per output Figure 3 shows only one device per output to simplify the diagram NMEA Listener device s 1 2 and 4 These devices conform in full to the NMEA 0183 standard and their connection ID s match that of the NBF 1 Simply connect like for like to A to A etc NMEA Listener device 3 This device does not conform in full to the NMEA 0183 standard and is a single ended device Connection of single ended devices to a differential output must be done with caution Connect device s to the NBF s A and its G Ground to an RS232 output Gnd Listener device 3 should now be able to receive the NMEA data cor
9. ection of these wires should be connected at the instrument end only to prevent ground loops Refer to the Specifications section for the full details on input output specifications If the laptop PC to be used with the NBF 1 does not have an RS232 serial port available the Actisense USB to RS232 adapter cable has been tried and tested to provide a compatible communications port Please visit the Actisense website for full details on this and other Actisense products Higher quality cable will naturally yield higher performance higher Signal to Noise Ratio SNR Page 7 Actisense Input Connections OUT L io EALA Battery Power Supply NMEA Talker A E o U Ma bt ak a Te o see ee eS SS eee d Aj R5232 ae OUT NMEA Talker B He M m i Tx G Personal Computer Figure 2 Input connections NMEA 0183 Input The NMEA 0183 differential opto isolated input is designed to handle a variety of NMEA 0183 device output specifications Please determine from device manufacturer s information if the device required to be connected to the Actisense NBF 1 conforms in full to the NMEA 0183 network communication standard If it does not the flexible Actisense NBF 1 inputs should still be capable of interfacing with the device though this is not guaranteed The diagram figure 2 above shows
10. iate CE approved shielded connectors and cabling used in accordance with the CE directive EN60945 Any EMC related issues should be reported to Active Research immediately to allow the company to rectify or resolve EMC related problems in accordance with its obligations under EN60945 If the unit is connected such that compliance failure occurs beyond the company s control the company shall not be held responsible for compliance failure until suitable EMC guidelines for connection are seen to have been taken Notices When using this document keep the following in mind The products described in this manual and the specifications thereof may be changed without prior notice To obtain up to date information and or specifications contact Active Research Limited or visit the Actisense website www actisense com Active Research Limited will not be liable for infringement of copyright industrial property right or other rights of a third party caused by the use of information or drawings described in this manual All rights are reserved The contents of this manual may not be transferred or copied without the expressed written permission of Active Research Limited Active Research Limited will not be held responsible for any damage to the user that may result from accidents or any other reasons during operation of the user s unit according to this document The NBF 1 does not validate the NMEA data it receives in any way
11. l maximum of 36 listeners simultaneously using the Actisense NMEA Buffer The NMEA signals The NMEA 0183 system v2 0 and later uses a differential signalling scheme whereby two wires are used to transmit the NMEA data These connections will be labelled as either NMEA A and B or NMEA and respectively depending on the instrument and manufacturer When connecting between different manufacturers there can be some confusion but it is simple and easy to remember NMEA A connects to NMEA and NMEA B connects to NMEA 2005 Active Research Limited The different NMEA standards The NMEA 0183 specification has slowly evolved over the years SO connecting one device to another is not always a straight forward matter The earlier versions of NMEA 0183 before v2 0 as detailed above used slightly different connection methods and signal levels the instruments had just one NMEA data line Tx or Out and used the ground as the other line similar to the way a computer serial port works This connection method is referred to as single ended instead of the differential method used by NMEA 0183 v2 0 devices The data format is largely the same between both systems with v2 0 adding some extra sentence strings and removing older redundant sentence strings from the specification The situation is further complicated as many manufacturers still use the
12. ly Page 9 Troubleshooting guide This guide will concentrate on all relevant troubleshooting issues above simple cable connection faults Therefore the cables between the NBF 1 hardware and any other devices should be checked as a matter of course before continuing with this guide Required user response Ensure that correct polarity of the NMEA connections have been observed NMEA connections are polarity sensitive No data seen on and A connections should be wired to the NBF s A NMEA instrument display and B connections should be wired to the NBF s B No damage should be caused if the polarity is reversed but no NMEA data will be seen on the receiving instrument Ensure that the PC software is selecting the correct PC Comms port number As a diagnostic you can use the standard Windows HyperTerminal utility to receive NMEA data By setting the input comms port to the one the NMEA NBF 1 is connected to the baud rate to that required 4800 normally no parity 1 stop bit 8 data bits and no flow control the received NMEA text data from the NBF 1 will be shown on the PC screen No data seen on PC display Table 1 Troubleshooting guide 2005 Active Research Limited Page 10 NMEA Buffer NBF 1 B Specifications Conan Cc ai Al OTT Supply voltage 12v Supply current see note 1 pply g Supply voltage 24v NMEA 0183 RS422 Logical 1
13. old single ended method of connection because it is cheaper to implement So how can an older type NMEA device be connected to a newer type device Care is needed it is possible to damage or overload the output of a newer differential device if it is incorrectly connected to an older device This is because the older devices used ground as the return whereas the newer devices actually drive the NMEA B line between 5v and Ov Thus connecting this output to ground will result in high currents being drawn by the driver instrument resulting in potential overheating and damage to the driver circuits To connect a new type differential device to an old type single ended system connect the NMEA A output from the differential driver to the single ended NMEA Rx or In input of the device Leave the NMEA B output floating Connect the ground line of the differential output device to the ground of the single ended device This provides the required data signal return current path To connect an old type single ended device to a new type differential device connect the NMEA Tx or Out output from the single ended driver to the differential NMEA A input of the device Connect the ground line of the single ended output device to the NMEA B input of the differential device This provides the data signal return current path If the NMEA B input is left floating then data
14. r communication ports as well as still being fully compatible with the latest NMEA 0183 standard devices Wide battery input voltage range to offer maximum compatibility the NMEA 0183 Buffer NBF 1 can operate from a battery supply anywhere between 8 and 35 volts Very low power consumption that is typically 6mA with no load and 70mA with all 6 outputs loaded on a 12 volt system This normally reduces to 4mA and 36mA respectively on 24 volt systems Very tough Polycarbonate case is certified to IP66 classified as totally protected against dust and protection against low pressure jets of water from all directions Being Polycarbonate it is also incredibly strong offering a wide temperature range and superior protection to the electronics inside The IP66 rating of the case is only limited by the sealing gasket strip which can be enhanced by applying a suitable non acid based marine sealant to the gasket after wiring and testing This will allow use of the unit in areas where salt spray could enter accidental immersion may occur or in environments where maximum long term reliability is paramount Robust ABS grommets are certified to IP68 classified as immersible for long periods without water ingress Note that to achieve this level of water integrity all grommets must be occupied by round section cables Large range of possible cable diameters of between 4 5 mm and 10 mm single or multi pair wire types can be easily ac
15. rectly though this is not guaranteed The NBF s B must never be connected to the ground of a single ended receiving instrument The resulting extra load may in the worst case damage the output driver Personal Computer Whilst the RS232 outputs are primarily designed for connection to a PC most PC s are capable of reading the NMEA 0183 outputs as well Simply connect to Rx and G to Gnd on a standard D type probably male connector 2005 Active Research Limited NMEA 0183 RS232 Outputs The RS 232 outputs can be connected to a PC s communication port older NMEA devices as well as the very latest NMEA instruments NMEA Listener devices 6 and 7 These devices conform in full to the NMEA 0183 standard Simply connect the devices or A to the NBF s Tx and the devices or B to the NBF s Gnd NMEA Listener device 5 This device does not conform in full to the NMEA 0183 standard and is a single ended device However the flexible outputs of the NBF should be able to drive this device if the device s is connected to the NBF s Tx and its G Ground to the NBF s Gnd Personal Computer The RS232 outputs are the preferred output for connection to a PC Connect PC s Rx Pin 2 on a standard 9 Pin D type to NBF s Tx and its G Ground Pin 5 on D type to Gnd Note 1 Wire colours are for guidance on
16. s and indeed surpasses all of the NMEA 0183 requirements Alternately if the vessel has two or more NMEA devices that are supplying the NMEA information the system solution could be to use the Actisense NMEA Data Combiner NDC 2 or NDC 3 Full information on the complete Actisense product range can be found on the Actisense website Page 4 NMEA Buffer NBF 1 B NMEA 0183 Introduction Designed over 20 years ago the NMEA 0183 standard has slowly become the common method by which marine electronics devices talk to one another The standard specifies both the electrical connections that make up an NMEA system and the format of the data sentences that carry the NMEA information The NMEA 0183 standard is a purely digital data transmission scheme using 1 s and 0 s in a binary format to communicate a digital representation of the required information depth speed etc to connected instruments Electrical specifications The latest specifications for NUEA0183 version 2 onwards are similar to the RS422 standard They use 5v and Ov signalling which is low voltage and can be interfaced to computer equipment with an Actisense Opto isolated adapter cable In older equipment version 1 however voltage levels could be much greater up to 15v as the original specification used 12 15 volt signalling which is similar to the standard RS232 computer communication ports The NMEA 0183 specification
17. stop bit Logical 0 start bit Maximum is under 35v overload condition Required level for NMEA to be detected Input voltage between KR ols O o 16 Input current Differential input voltage OJ N w a 2 ajoo jola Output voltage between and ground Logical 1 stop bit see note 2 O1 NO At maximum load drive voltage Output current see note 2 reduces to 2v QOJ W OJ N Output short circuit current Baud rate 38 4 Kbit sec NMEA 0183 RS 232 Output voltage swing on A NO Co fe O Loaded with 3KQ to Ground RS232 Vout 2v I Ql I co 100 Output resistance Output short circuit current Infinite duration CO N Baud rate O Data propagation delay Table 2 NBF 1 specifications All specifications are taken with reference to an ambient temperature T of 25 C Note 1 Current consumption measured under no load and full load conditions 2 NMEA output is RS 485 compatible 2005 Active Research Limited Page 11 Actisense Company Information Active Research Limited 5 Wessex Trade Centre Ringwood Road Poole Dorset UK BH12 3PF ctisense Telephone 01202 746682 International 44 1202 746682 Fax 01202 746683 International 44 1202 746683 Actisense on the Web For advice support and product details E mail support actisense com Website www actisense com Active Research on the Web For
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