Thanks! I'll take a look into it!
While you are looking at it, please bear in mind that
Daylight Savings Adjustment is not, repeat
not, automatically applied by the RTC module, or the processor.
Logix5000 controllers are sold all over the world, and there are various ways in which daylight saving time is implemented, this
Wiki article is an eye-opener !
To use the Daylight Savings Time correctly, you have to put program code in the controller to turn on and off the "Apply DST" (SINT) at the correct dates and times.
You must also set the number of minutes to apply in "DSTAdjustment" (INT) - this is added to the "DataTime" object to create the "LocalDateTime" object.
You use SSV to set these attributes/objects.
Using the controller's DST adjustment is much easier than "rolling your own"... You don't have to worry about triggering it twice when you "put the clocks back". Here in the UK we "Spring forward, Fall back", by 60 minutes.
So in the fall (last Sunday in October) we turn off the "ApplyDST" (zero value) at 0100 hrs UTC, so that will be 0200 hrs BST becoming 0100 hrs.... then an hour later the GSV will simply "turn it off again" (by detecting 0200 hrs again), which will have no effect. One extra GSV each year isn't going to have much of an effect, and there's no need to trap it happening, unless you are totally OCD !
That Wiki article is a good read, see if you can spot the obvious anomolies to what most people call a "standard"....