Dennis,
ik begrijp Nederlands, maar dit is een mondiale site, dus gebruik ik Engels, dan kan iedereen volgen.
I do have a TP170B (6AV6 545-0BC15-2AX0), but I only knew about the possibility to set a date and a time format. Maybe you have a more recent version.
I don't see the use of a real-time clock if there is no battery backup. After all, in that case, power out means clock is dead. That's the reason I use the clock from the PLC as suggested by RRobbins.