write method
Implementation
Future<int?> write(int slave, Uint16List argData, int addr,
QualifiedCharacteristic writer,Function listen,
{int retry = 5, int timeout = 500}) async {
Uint8List data = ModbusPtl.writeRegister(slave, addr, argData);
List<int>? ret = await call(data, writer, listen);
if (ret == null) return null;
Tuple4<int, int, int, int>? recv = ModbusPtl.r_modbus_write(Uint8List.fromList(ret!));
return recv?.item4;
}