Monitor status of I/O in S7-300

Hello

I am having some problems with a system that has been running for some time now, it seems that some times a sensor fails, so my question is, does any of you have a good idea how to make some sort of long time monitoring of 2 inputs and a couple of memory bits.

I am thinking that some sort of graph (Chart), showing my inputs and memory bits together.

Any ideas.

Regards Brian

Here's some code that logs the state of 8 bits together with the time and date on each 0 to 1 and 1 to 0 transition of a given variable. The example code is triggered by transitions on I0.0 (logged to DB1) and I0.1 (logged to DB2). I split the date_and_time into bytes and TOD for ease of monitoring when testing.

Great piece of software, I think this will do the trick.

Thanks a lot.

Best regards
Brian