Are you sure you got a full, aligned packet? It starts with ZZ , counted length, no missing characters?
The DLPlus checksum is correct. More likely you're misaligned, or somehow
dropped, swapped, or corrupted a character.
Here is the C# code too for comparison
public byte Checksum(byte[] ary, uint ofs, uint fence)
{
uint sum = 0;
for (var i = ofs; i < fence; i++)
sum += ary[i];
return (byte)((~sum) & 0xff);
}
Welcome to the cabal of TPDD protocol initiates.
-- John.
