Real Time Clock From HMI

[Eddie Willers]

the HMI is sending the correct time every 60 seconds

That's consistent with the 60 second update rate that is configured in the Global Connections window.

Check the cross-reference for N10:0 and N10:1 very carefully in your program.

And check carefully to be sure that the PV+ application isn't writing a value to those addresses elsewhere.

 

[dternosky]

this is the cross ref and the MOV goes to an integer file and isnt being used anywhere else not sure why its doing this. no documentation on these instructions. I appreciate all you input on this matter. Thanks!

 

[widelto]

Dave , can you show us those MOVs on File #2 Main rung 6.

 

[Eddie Willers]

The cross-reference doesn't tell you if an instruction is the source or the destination of an instruction, so we can't tell if that's an over-writing instruction or not.

The cross reference does tell us that the N10 file isn't being used in any file operations (like COP or FLL or FAL) that would write over sections of the file.

 

[Mickey]

its a micrologix 1200

The ML1200 has a RTC module. If you don't have one you can get one. See PDF

 

[dternosky]

the one picture shows the move of N10.0 and N10:1 to N19 and N20. the other picture shows the cross reference on N19 and N20. N19 and N20 are not used anywhere else in the program. I am not sure what they are using these registers for.

 

[dternosky]

I ran a trend on N10:1 and it displays what i am talking about with the time jumping consistently. You can see when the HMI updates the time then it falls back.

 

[Mickey]

Post your program, its .RSS file if you can. Zip it first

 

[dternosky]

here is the file

 

[arlenjacobs]

Can you cut out the PVP?
Power off the PVP and then test again, using RSLogix to change the N10:1 value manually.

You could also try putting the PLC into program mode with the PVP powered on. Trend N10:1 again and see what happens to the value then.

 

[JasonTheSparky]

Maybe Ken would have a little more insight, but I am inclined to think that the problem lies in the HMI project. Possibly an error in an expression syntax or multiple updates of values...? I did not see anything in this ladder project that would change or alter the values in N10:0 or N10:1.

I did notice though that in LAD 5, rung 4 you are counting 61 minutes in an hour, not that it has anything to do with the issue at hand...