System Clock PLC M340 - Unity Pro

[bogu]

%S50 set but %SW50-52 keep changing

You have to use system bit %S50 and words %SW49-%SW53 for this.

When you want change time, set bit %S50 first, then copy new time to system words %SW49-%SW53. (Use integer to BCD conversion before copy) and set bit %S50 to "0" for updating time to RTC.

To get hours and minutes separate, you can use Rotate right and left instructions. Not easiest way, but it is possible

For reading time from system words, use first BCD to integer conversion and then rotate left/right instructions.

Probably misunderstanding something. I set %S50, but the registers %SW50-52 keep changing. Should they not 'disconnect' from the system so I can change them?
- confused

 

[ganutenator]

I'm late to the party, but this is what I used for the M340.
Disclaimer: I did not write this. It came mostly from Schneider.

(*
RTC_Compare:= EQUAL_ARINT(Hours_6,Hour_memory_6);*)
(*EQUAL_ARINT(Hours_6,Hour_memory_6) > -1*)
IF  (*(RTC_Compare > -1) or *)hmi_set_clock THEN (*if time/date set words were changed, then set clock*)

SET(%S50);

%SW50 := INT_TO_BCD(Hours_6[2] * 100);(*seconds*)
%SW51 := INT_TO_BCD((Hours_6[0] * 100) + Hours_6[1]);(*hours and minutes*)
%SW52 := INT_TO_BCD((Hours_6[3] * 100) + Hours_6[4]);(*month and day*)
%SW53 := INT_TO_BCD(Hours_6[5]);(*year*)

hmi_set_clock:= 0;

ELSE (*if no change in set words, just update them to the clock values*)
(*display hh mm ss mm dd yyyy MW2161-MW2166 *)
(*
Hours_6[0] := BCD_TO_INT(%SW51 / 256);(*hours*)
Hours_6[1] := BCD_TO_INT(%SW51 MOD 256);(*minutes*)
Hours_6[2] := BCD_TO_INT(%SW50 / 256);(*seconds*)
Hours_6[3] := BCD_TO_INT(%SW52 / 256);(*month*)
Hours_6[4] := BCD_TO_INT(%SW52 MOD 256);(*day*)
Hours_6[5] := BCD_TO_INT(%SW53);(*year*)
*)


	IF (%S50) THEN
		RESET(%S50);
		
	END_IF;

END_IF;

Hour_memory_6 := Hours_6 ;(*set memory words to detect any change next scan*)




(*used in the hmi to see if the plc is in run*)
plc_second2 := BCD_TO_INT(%SW50 / 256);(*seconds*)