S7-1200 counting pulses

Hi everyone!

I am using the S7-1200 1212DC/DC/DC cpu to count pulses on two inputs. The code involves counting of pulses on I0.0 in such a way that the pulse is counted for a second, once a second is completed the counter is reset to 0, the counted value is moved to another MW from where it is converted into a string, and then appended to another long string so that it contains 60 values, for 60 seconds.

The issue is, the count is being missed. I have even tried simulating the count with using 2.5Hz internal clock but the values get Missed out.