Hi Szabi, Thanks for that. I can now run my servo properly. Last night I got it to turn through 90 degrees but very slowly. I think I had programmed the servo speed to be 20 because your printed instructions say "1 - slow, 20 - fast". In you answer above, 1 = fast and 20 = slow so I tried accessory address = 0020 when the LED was fast-flashing and now the servo turns faster. So thanks! But you do need to correct your printed instructions ( and the pdf on this site). Duncan