Program Life

If I unplug power from a 1212C DC/DC/DC PLC,  How long will the program be retained in the memory of the PLC?

KvdM

If I unplug power from a 1212C DC/DC/DC PLC,  How long will the program be retained in the memory of the PLC?

Hello KvdM,

if you use a memory card with your CPU as a program card (see SIMATIC S7 S7-1200 Programmable controller, PLC concepts->Using a memory card), then your program should be retained for 10 years, according to techn. specs of memory card.

regards

What if no memory card is used?

KvdM

If I unplug power from a 1212C DC/DC/DC PLC,  How long will the program be retained in the memory of the PLC?

 If someone told me the PLC will retain its program for several years..
I will believe them. I however do not find any specification that says so.

Out of experience I know that we have shipped machines that was powered ON after 2 months and even the settings (retention DB) was still as I calibrated the machine. I do not expect the retention to be less that 5 years. The REAL TIME CLOCK is however another matter - specified at 12 - 20 days.

On the older generation S7-200, I had to refurbish systems that was shut down for 2 years or so - and the program was still in place.. the parameter settings were however not retained for that case.

When sending equipment on a long sea voyage, I would say you are okay.

There is however nothing wrong with preparing a backup MMC card for the client so that he can load a new PLC with the card if something goes wrong with the shipping... and let him pay for the MMC card.

Greetings.
w