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Navman 11 User Manual

Page 12

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12

MN002000A © 2004 Navman NZ Ltd. All rights reserved. Proprietary information and specifications subject to change without notice.

Field Type

Symbol

Definition

Special format fields

Status

A

Single character field:

A = yes, data valid, warning flag clear

V = no, data invalid, warning flag set

Latitude

1111.11

Fixed/variable length field (degrees/minutes.decimal) two fixed digits of degrees, two fixed

digits of minutes, and a variable number of digits for decimal-fraction of minutes

Note: Leading zeros always included for degrees and minutes to maintain fixed length (the

decimal point and associated decimal-fraction are optional if full resolution is not required).

Longitude

yyyyy. yy

Fixed/variable length field (degrees/minutes.decimal) three fixed digits of degrees, two fixed

digits of minutes and a variable number of digits for decimal-fraction of minutes.

Note: Leading zeros always included for degrees and minutes to maintain fixed length (the

decimal point and associated decimal-fraction are optional if full resolution is not required).

Time

hhmmss.ss

Fixed/variable length field (hours/minutes/seconds.decimal) two fixed digits of hours,

two fixed digits of minutes, two fixed digits of seconds and a variable number of digits for

decimal-fraction of seconds.

Note: Leading zeros always included for hours, minutes, and seconds to maintain fixed

length (the decimal point and associated decimal-fraction are optional if full resolution is not

required).

Defined

field

Some fields are specified to contain pre-defined constants, most often alpha characters.

Such a field is indicated in the NMEA-0183 standard by the presence of one or more valid

characters. The following characters and character strings used to indicate field types are

excluded from the list of allowable characters: ‘A’, ‘a’, ‘c’, ‘hh’, ‘hhmmss.ss’, ‘1111.11’, ‘x’, and

‘yyyyy.yy’.

Numeric value fields

Variable

numbers

X.x

Variable length integer or floating point numeric field (optional leading and trailing zeros)

Note: The decimal point and associated decimal-fraction are optional if full resolution is not

required (eg 73.10 = 73.1 = 073.1 = 73).

Fixed HEX

field

Hh__

Fixed length HEX numbers only, most significant bit on the left.

Information fields

Variable

text

Cn C

Variable length valid character field

Fixed

alpha field

Aa__

Fixed length field of uppercase or lowercase alpha characters

Fixed

number

field

Xx__

Fixed length field of numeric characters

Fixed text

field

Cc__

Fixed length field of valid characters

Note 1: Spaces may only be used in variable text fields.

Note 2: A negative sign (‘–’ or 2DHEX) is the first character in a field if the value is negative. The sign is omitted if the value is

positive.

Note 3: All data fields are delimited by a comma (,).

Note 4: Null fields are indicated by no data between two delimiters.

Table 3-3 NMEA field type summary

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