RTC function in Codesys vs TwinCAT

[AlfredoQuintero]

To Codesys and TwinCAT experts, if you could spare some time to help this newbie, I will be so very grateful, just please promise not to laugh too raucously at my ignorance.


Months ago I managed to write a simple Codesys program that measures the time the PLC program has been up and running using the RTC (Real Time Clock) function, but what a head scratch I have hit when trying to do the same with TwinCAT. I use a first scan bit to get an initial time in the TwinCAT, but even though the EN bit is FALSE, this RTC is executed every scan, thus I have no initial time to subtract. After much head banging I have swallowed my pride and herewith cry for help.

 

[Jkoso]

Just remove that RTC_0 and get time with MOVE from RTC-2 that same first scan bit. In TC3 rtc block works different compared to codesys. It will run every scan if it is initialised once. EN input is only re-initialisation.

 

[AlfredoQuintero]

Jkoso. Thanks very much. I feel embarrassed I did not figure this one out, but you have helped me a lot. If you were in Yokohama I would want to invite you a pint or two.