www.pudn.com > SerialGPS.zip > ReadPacketTerminator.m

function cksum = ReadPacketTerminator(gps) 
% ReadPacketTerminator Read the three byte sequence terminating a packet 
global pid_dle_byte; 
global pid_etx_byte; 
    
% Read checksum byte. If it is equal to DLE, read (and discard) the 
% following DLE. 
cksum = fread(gps, 1); 
if (pid_dle_byte == cksum) 
    d = fread(gps, 1); 
    if (pid_dle_byte ~= d) 
        error(['CKSUM == DLE, but DLE not repeated.']); 
    end 
end 
 
% Read the DLE and ETX that terminate this packet 
byte = fread(gps, 1); 
if (pid_dle_byte ~= byte) 
    ExpectedDataError(byte, pid_dle_byte); 
end 
byte = fread(gps, 1); 
if (byte ~= pid_etx_byte) 
    ExpectedDataError(byte, pid_etx_byte); 
end