gnssSatellitesInView (Function)

Retrieves information about the satellites in view.

This can be used to help with determining the local signal conditions and position accuracy.

Input:

type : SINT (Default: 0)

0 = GPS

1 = GLONASS

2 = GALILEO.

3 = BeiDou.

tracked : BOOL Default TRUE

Retrieve satellites that are being tracked.

untracked : BOOL Default FALSE

Retrieve untracked satellites.

gnss : BOOL Default TRUE

Retrieve normal positioning satellites.

sbas : BOOL Default FALSE

Retrieve SBAS satellites.

Output:

satellites :  gnssSatellites

STRUCT_BLOCK with space for information about 30 satellites:

id[n]: SINT

Satellite ID.

elevation[n]: SINT

Elevation angle for satellite n.

azimuth[n]: INT

Azimuth angle for satellite n.

SNR[n]: SINT

Signal to noise ratio for satellite n. If the satellite is untracked, the SNR will be 120.

Returns: INT

Number of found satellites matching the filter

Declaration:

STRUCT_BLOCK ALIGN gnssSatellites;

  id        : ARRAY [1..30] OF SINT;

  elevation : ARRAY [1..30] OF SINT;

  azimuth   : ARRAY [1..30] OF INT;

  SNR       : ARRAY [1..30] OF SINT;

END_STRUCT_BLOCK;

FUNCTION ALIGN gnssSatellitesInView: INT;

VAR_INPUT

   type        : SINT := 0;

   tracked     : BOOL := TRUE;

   untracked   : BOOL := FALSE;

   gnss        : BOOL := TRUE;

   sbas        : BOOL := FALSE;

   satellites : ACCESS gnssSatellites;

END_VAR;

END_FUNCTION;

Example:

INCLUDE rtcu.inc
 
PROGRAM test;
VAR 
   sats  : gnssSatellites;
   gnss  : gnssFix;
   count : INT;
   i     : INT;
END_VAR;
 
gpsPower(power := ON);
 
BEGIN
   gnss();
   IF gnss.mode > 1 THEN
      count := gnssSatellitesInView(type:=0, satellites:=sats, 
      sbas:=FALSE, untracked:=FALSE);
      DebugFmt(message:="satellites tracked: \1", v1:= count);
      FOR i := 1 TO count DO
         DebugFmt(message:="      SVID=\1, El=\2, Az=\3, SNR=\4",
                  v1:=sats.id[i], v2:=sats.elevation[i], v3:=sats.azimuth[i], v4:=sats.SNR[i]);
      END_FOR;
   END_IF;
END;
END_PROGRAM;