FPΣ User's Manual 
 
3.6 Clock/Calendar Function 
35 
3.6 Clock/Calendar Function 
The clock/calendar function can be used if the backup battery (see page 95) is installed in the 
FPΣ. There are no default clock/calendar settings, so the programming tool or another means 
must be used to specify these values. 
 
3.6.1  Memory Area for Clock/Calendar Function 
With the clock/calendar function, clock and calendar data stored in special data registers 
DT90053 to DT90057 can be read and used in sequence programs. To access special data 
registers and special internal relays, use the PLC-independent system variables. 
X: Available, –: not available 
Special 
data 
register 
FPWIN Pro 
system variable 
Upper byte  Lower byte  Reading  Writing 
DT90053  sys_w_RTC_HourMin 
Hour data 
16#00–16#23 
Minute data 
16#00–16#59 
X – 
DT90054  sys_w_RTC_MinSec 
Minute data 
16#00–16#59 
Second data 
16#00–16#59 
X X 
DT90055  sys_w_RTC_DayHour 
Day data 
16#01–16#31 
Hour data 
16#00–16#23 
X X 
DT90056  sys_w_RTC_YearMonth 
Year data 
16#00–16#99 
Month data 
16#01–16#12 
X X 
DT90057  sys_w_RTC_DayOfWeek – 
Day-of-the-week data 
16#00–16#06 
X X 
DT90058 
sys_w_RTC_Set 
Bit 15=TRUE (16#8000): activates 
clock/calendar setting 
Bit 0=TRUE (16#0): sets seconds to 0 
X X 
 
3.6.2  Settings for Clock/Calendar Function 
The clock/calendar values are backed up using a battery. Therefore, the clock/calendar 
function cannot be used unless a battery has been installed. 
There are no default clock/calendar settings, so the programming tool or another means must 
be used to specify these values. There are two ways to set the clock/calendar function: 
Using the programming software 
1. Online → Online Mode 
2. Monitor → Display Special Registers → Calendar Functions 
3.  Enter the desired date and time values