Writing to RRTC on a M580

[Super_88]

I'm trying to write my HMI server time to the RRTC on a M580. I have been referencing the technote:

"In the M580 CPU, why does the system word %SW51 (RTC Hour) show a different value?"

I'm reading from the RRTC just fine using this note. I can also write to the system variables (%SWXX), but not the hour. Is there an elegant way to write to the RRTC that doesn't use the defunct  system word %SW51 (RTC Hour)?

Thanks,

[Trinxs1]

I am not sure why you are having the issue.  Please note that the RTC is organized as per the attached document.  %SW51 is expressed in hex and contains 16#HHMM where HH is the hexadecimal equivalent of hours 0-23 and MM is 0-59 minutes.

see the system word manual..  https://www.se.com/au/en/download/document/EIO0000002135

[MatthewM]

The M580 uses UTC in one and local time in the other.  I can't remember which way around.  That will account for your different values.  We had to modify our PLC clock RTC sync DFB to accommodate this difference from the M340.

[ciupol]

RRTC block has only outputs so you will not be able to write to it.

I believe you should be able to use local time with WRTC_DT block.

[JeriLester578]

I am not sure why you are having the issue. Please note that the RTC is organized as per the attached document. %SW51 is expressed in hex and contains 16#HHMM where HH is the hexadecimal equivalent of hours 0-23 and MM is 0-59 minutes.