Real Time Application

[TimWilborne]

Well anyone can mess with the clock and screw it up but their isn't much we can do about that.

Now like I said daylight savings time does not affect the CurrentValue if you set the clock properly which I would doubt many people do. In order to set it properly you have to use the CurrentOffset also. Come to think of it this is only the second time I have seen where it would matter.

 

[TConnolly]

I mentioned using a PLC GPS module to get the time before, but if someone changing the time clock on the PLC is a concern then I strongly suggest using one of these:

http://www.hiprom.com/Products/1769hpGPS/1769hpGPS.htm

Write your program to actually use the time from this module instead of the PLCs DateTime variable. Then it really wouldn't matter what anyone did with the PLCs clock setting. They would have to physically rewrite the program to screw things up. Local:SLOT:I.Data[1] thru Data[7] would contain the precise date and time.

 

[TimWilborne]

Looks like it also gives it to you in either the 7 DINT or 2 DINT format.

Has anyone been able to use one of these modules yet? I'd like to hear about some experiences with it

 

[504bloke]

The people at JTides did a great job in creating a Java program to output tide charts in Excel for nearly anywhere in the world.

Look up table would be the best way, I am just doing a flood defences pumping station, doing the HMI software right now! (Without the 30 year bit though!!)

Interesting JTides, just emailed the father in-law the webpage as he's a sailing nutter and i dont think he has that software!

Thanks for the JTides info...

 

[TConnolly]

Looks like it also gives it to you in either the 7 DINT or 2 DINT format.

Has anyone been able to use one of these modules yet? I'd like to hear about some experiences with it

The manul has the following:

The 1769HP-GPS module reports UTC as a 64 bit unsigned long integer representing the number of elapsed microseconds since 1 January 1972. This UTC value is thus independent of the Configured Time Zone.

But I can't see where in the configuration that you can set it to return that 64bit unsigned long in the image table.

 

[inductiveautomation]

If running this task on a computer isn't overkill, it'd be trivial to accomplish with FactorySQL. You would simply import the .CSV file to any SQL database. FactorySQL would run a periodic SQL query that selects your parameters based on the date/time (a single SELECT query), then writes the results to some PLC registers. That's it! Or if you'd like, you could have the PLC toggle a specific register to trigger FactorySQL to perform the above task.

 

[Gerry M]

I think another issue is that nobody wants to see a 8" pipe spewing effluent into the ocean (ahem)

Ahhh! the real reason. I found this response ammusing because just as I was hitting the reply button to my last post I thought of the same thing. I can just imagine the political problems of operating at low tide. Hey what's that smell?