Question:
Why is the memory location for the stress counters and switching cycle counters (C0177/x) with the 8400 not on the memory module, but directly in the device (exactly: in the base unit (BU))?
Answer:
In this way, the counter contents stored fail-safe will remain with the corresponding device hardware. The attached memory module may also come from a different device, e. g. when a device is replaced.
Search terms: fail-safe, memory module, stress counter