In the NMEA Setup of GpsMap76 and the Advanced NMEA Setup of
GpsMap276C, there is a recommendation to not select all messages to be
sent, since this could lead the time of transmission to exceeds 1 sec,
which could impact the performance of the interface with some
equipments, like autopilots.

After the 3.21 upgrade, wich included the 3 new messages (BWC, XTE and
VTG) that I have requested to be included in the Map276C, the maximum
batch would have about 16 messages like this:

$GPRMC,010003,A,1248.7047,S,03827.5797,W,0.0,94.9, 290505,23.0,W,A*03
$GPRMB,A,0.04,L,AIC,BA01,1248.4128,S,03827.6978,W, 0.314,338.4,,V,A*33
$GPGGA,010003,1248.7047,S,03827.5797,W,1,11,0.8,1. 0,M,-10.5,M,,*66
$GPGSA,A,3,01,03,06,,14,15,16,18,19,21,22,25,1.5,0 .8,1.3*3B
$GPGSV,3,1,12,01,43,333,54,03,43,237,49,06,05,030, 43,09,02,120,00*7C
$GPGSV,3,2,12,14,86,032,47,15,46,140,45,16,18,315, 47,18,19,143,49*70
$GPGSV,3,3,12,19,21,221,35,21,29,091,49,22,39,174, 43,25,17,000,50*70
$GPGLL,1248.7047,S,03827.5797,W,010003,A,A*43
$GPBOD,345.6,T,8.6,M,BA01,AIC*04
$GPBWC,010003,1248.4128,S,03827.6978,W,338.4,T,1.5 ,M,0.314,N,BA01,A*61
$GPVTG,94.9,T,117.9,M,0.0,N,0.0,K,A*19
$GPXTE,A,A,0.04,L,N,A*07
$PGRME,6.7,M,9.5,M,11.6,M*15
$PGRMZ,3,f,3*18
$PGRMM,WGS 84*06
$GPWPL,1249.4946,S,03830.9732,W,USIB*4F


This batch has 742 characters, and thus, the time to send it at 4800
bps is: 742*8/4800= 1.23 sec, which would exceed the recommended
maximum of 1 sec.

Excluding all the optional messages, as allowed in the NMEA setup,
(GSA, GSV, WPL , RME, RMZ and RMM) the batch would consist of 8
messages as follows:

$GPRMC,010003,A,1248.7047,S,03827.5797,W,0.0,94.9, 290505,23.0,W,A*03
$GPRMB,A,0.04,L,AIC,BA01,1248.4128,S,03827.6978,W, 0.314,338.4,,V,A*33
$GPGGA,010003,1248.7047,S,03827.5797,W,1,11,0.8,1. 0,M,-10.5,M,,*66
$GPGLL,1248.7047,S,03827.5797,W,010003,A,A*43
$GPBOD,345.6,T,8.6,M,BA01,AIC*04
$GPBWC,010003,1248.4128,S,03827.6978,W,338.4,T,1.5 ,M,0.314,N,BA01,A*61
$GPVTG,94.9,T,117.9,M,0.0,N,0.0,K,A*19
$GPXTE,A,A,0.04,L,N,A*07

This batch has 412 characters, and thus, the time to send it at 4800
bps is: 412*8/4800= 0.69 sec, well below the recommended maximum of 1
sec.

So, I remind the owners of Map276C to pay attention to this setup,
letting the unit send only the optional messages if needed; selecting
a batch between this two extremes would be advised.

Pascal