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4

Connections

Real-time or buffered inputs

Before connecting NMEA inputs to your NMEA Multiplexer, 
consider whether they should be connected as real time or 
buffered inputs:
• Data running at a fast rate and consisting of single sentences, 

particularly time-critical data, should be connected to either 

NMEA In 1

 or 

NMEA In2

, real time inputs. This includes 

data from devices such as Fast Heading Sensors, and Fluxgate 
Compasses. When data is processed in real time, some sen-
tences may be lost, but the timing of the data is maintained 
and there is no time delay. These inputs will store only one 
NMEA sentence at a time, and thus prevent unwanted delays.

• Slower data that is input as a burst should be connected to 

either 

NMEA In 3

 

or 

NMEA In 4

, as buffered inputs. This 

includes data such as GPS, route and depth information, for 
which the timing is less critical. These inputs can store multiple 
sentences (12 to 70, depending on length). This is necessary 
for devices such as GPS, which can output 10 sentences at 
once, every 1 or 2 seconds.

NMEA in

Connect an unused pair of 

NMEA In a

 and 

b

 terminals on the 

NMEA Multiplexer to the NMEA output port of each device from 
which you wish to receive NMEA data. The manner in which the 
connections are made depends on whether the device has a 
differential or single ended output, as follows:

Содержание NMEA Multiplexer

Страница 1: ...NMEA Multiplexer Owner s Handbook Document Number 81250 1 Date February 2005...

Страница 2: ...Copyright Raymarine UK Ltd 2005...

Страница 3: ...nd this guide EMC Installation Guidelines All Raymarine equipment and accessories are designed to the bestindustry standards for use in the recreational marine environment Their design and manufacture...

Страница 4: ...s willnotdamagetheequipment butmaycausethelossofsomeinforma tion and may change the operating mode Raymarine specified cablesare used Cutting and rejoining these cables cancompromiseEMCperformanceandm...

Страница 5: ...ii Introduction 1 Inputs outputs 1 NMEA inputs 2 Input priorities 2 NMEA outputs 2 Installation 3 Mounting 3 Connections 4 Real time or buffered inputs 4 NMEA in 4 NMEA out 5 Power supply 6 CAUTION E...

Страница 6: ...iv...

Страница 7: ...NMEA Multiplexer has Four NMEA inputs listener ports NMEA In 1 2 3 4 One NMEA output talker port NMEA Out One common terminal NMEA Out Com Data Overflow NMEA In 1a NMEA In 1b NMEA In 2a NMEA In 2b NME...

Страница 8: ...fed via a discrete buffer for each port Each buffer holds approximately 2 seconds of NMEA data Input priorities Data at the listener ports is prioritized so that each NMEA in port isread twiceasoften...

Страница 9: ...s shown in the following illustration D7556 1 Da ta Ov erflo w NMEA 0183 Multiplexer Da ta Ov erflo w NMEA 0183 Multiplexer 1 2 4 3 Place the NMEA Multiplexer at the intended location and mark holes f...

Страница 10: ...These inputs will store only one NMEA sentence at a time and thus prevent unwanted delays Slower data that is input as a burst should be connected to either NMEA In 3 or NMEA In 4 as buffered inputs T...

Страница 11: ...lexer NMEA out Device with single ended NMEA output Ground NMEA Multiplexer Note NMEA outputs from Raymarine products are differential Shield D7587 1 NMEA In a NMEA In b Device with differential NMEA...

Страница 12: ...uments and or computer Protect the power supply with a 0 5 A fuse The wires used to connect the power supply must be less than 50 m in length and have a total cross sectional area of at least 0 2 mm2...

Страница 13: ...s to make sure the cables are physically secure and cannot be accidentally pulled from their connectors Indicators Data indicator lit AgreenDataLEDblinkswhenvalidNMEAdataisreceivedatthe listener ports...

Страница 14: ...vices to different listener ports Both indicators lit Both LED s will blink once when power is applied to the NMEA Multiplexer If the red LED stays lit this indicates that a hardware error was found d...

Страница 15: ...d wire Current consumption 70 mA maximum with fully loaded talker ports Inputs 4 x NMEA 183 galvanically isolated Input resistance 800 Ohm Outputs 1 x NMEA 183 Buffers 2 buffers of 1000 characters NME...

Страница 16: ...r Road Portsmouth Hampshire PO6 3TD United Kingdom Tel 44 0 23 9269 3611 Fax 44 0 23 9269 4642 www raymarine com Raymarine Inc 22 Cotton Road Unit D Nashua New Hampshire 03063 4219 USA Tel 1 603 881 5...

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