Mazeeff,
We have released firmware with DSTON support in 3.02.17c and later firmware. This feature is NOT fully tested, because it depends on user to set PLC code to enable it.
Since DSTON feature will write to flash EEPROM chip, it will have write life 100,000 times by the chip manufacture. In normally use, if user only set once a year and unset once a year,
that will take 50,000 year to wear out the EEPROM. However, if the PLC code having bug and setup this ON and OFF constantly, it will not take more than 5 minute to finish 100,000 times.
With that warning, lets discuss the DSTON feature.
In the general tab, there is now a DSTON checkbox. That checkbox will add one hour to the clock when it is checked. When it is unchecked, it will not add one hour to the clock.
That is not really doing much. For DSTON to work automatically, user must have 3.02.17c firmware and add PLC code. As we have discussed in this thread, the differences in the whole
world on Day Light Saving is so different from country to country. Not only that, congress keeps changing the Day Light Saving start and end date, too. For the USA, the latest DST on and off
date is defined by US congress as:
"Starting in 2007, daylight time begins in the United States on the second Sunday in March and ends on the first Sunday in November. On the second Sunday in March, clocks are set ahead one hour at 2:00 a.m. local standard time, which becomes 3:00 a.m. local daylight time. On the first Sunday in November, clocks are set back one hour at 2:00 a.m. local daylight time, which becomes 1:00 a.m. local standard time."
To make it less CPU wasting, we check current day of the week is Sunday in the PLC code then going to the routine for further checking based on the above paragraph defined date.
START
TSTEQ CDW 0
CALLSUB CKDST
NOP
END
CKDST:
TSTNE CH 2
RET
TSTEQ CMONTH 3
CALLSUB CKDSTON
TSTEQ CMONTH 11
SET DSTON 0
RET
CKDSTON:
TSTGT CDAY 7
SET DSTON 1
RET
This code is not fully tested. If the location you are in is not in USA, this PLC code may not work for you. You will need to figure out the month and week for DST on and off for your region. If DSTON is already 1, keep setting that to 1 will have no effect, similarly if DSTON is 0, keep setting that to 0 will not harm the chip. Only keep setting it to 1 then 0, then 1, then 0, will actually write to eeprom.
