int start, int stop, boolean withData) throws Exception {
Buffer requestFrame = new Buffer(S);
requestFrame.writeBytes(buildHeader(FC, group, variation));
if (stop < 256) {
requestFrame.writeByte(START_STOP_8);
requestFrame.writeByte((byte) start);
requestFrame.writeByte((byte) stop);
} else {
requestFrame.writeByte(START_STOP_16);
requestFrame.writeBytes(start);