The chip manufacturer specifies a service life of 100,000 cycles, but doesn’t guarantee it. Since data memory is set up as a ring buffer, each data block is only written to once per run-through. Depending upon storage density, one run-through might take one day, or several months. The counter readings are saved to a flash memory location once every 15 minutes. However, 5 blocks are reserved as a fault tolerance and automatic advancing takes place in the event of an error. Thus far we haven’t had any such cases within a period of 5 years.