Time and Date ¶ Reading and setting of the realtime clock is already supported by modules of the library CAA_RealTimeClock.lib . These modules, however, might not take into account the time zone and a possible switch between summer and standard time. If an automatic switch is desired all the same, the function blocks of the CAA_DTUtility library can be used for reading and setting the realtime clock. In this case the time switch is done via this library. The switch between summer and standard time is not done until one of the function blocks GetDateAndTime or SetDateAndTime is called. For this reason it is recommended to read the system time cyclically via function block GetDateAndTime . If the runtime system supports the automatic switch between summer and standard time, the calls of the library will be forwarded directly to the corresponding functions of library CAA_RealTimeClock and the clock switch will be done by the runtime system. GetDateAndTime (FunctionBlock) SetDateAndTime (FunctionBlock)
GetDateAndTime (FB) ¶ FUNCTION_BLOCK GetDateAndTime This function block reads the realtime clock. It returns the time of the local time zone (i.e. a possible switch to summer/standard time will be regarded). The current time zone switch can be defined by SetTimeZoneInformation . If a switch to summer/standard time has become necessary since the last polling of the time, this is done automatically. At the start of the module the outputs dtDateAndTime and ePeriode are reset. ( DT#1970-01-01-00:00 and RTCLK_UNKNOWN ). After successful operation they will contain the current local time. InOut: Scope Name Type Comment Input xExecute BOOL Rising edge: Action start Falling edge: Resets outputs. If a falling edge occurs before the function block has completed its action, the outputs operate in the usual manner and are only reset if either the action is completed or in the event of an error. In this case, the corresponding output values (xDone, xError, iError) are present at the outputs for exactly one cycle. Output xDone BOOL Action successfully completed xBusy BOOL Function block active xError BOOL TRUE : error occurred, function block aborts action FALSE : no error eError ERROR Error description for diagnosis dtDateAndTime DT ePeriode RTCLK.PERIODE Current local time
SetDateAndTime (FB) ¶ FUNCTION_BLOCK SetDateAndTime This function block sets the realtime clock. The current local time is passed in the parameter dtDateAndTime . Note If the time is within the not-unique interval shortly after the switch to standard (winter) time, standard time will be assumed. This case occurs for example in the Central European countries, if on the last Sunday of October the time is set at 2:30 a.m.. Here it is not clear, whether 2:30 a.m. is still summer time or already standard (winter) time. In this case the module assumes standard (winter) time. InOut: Scope Name Type Comment Input xExecute BOOL Rising edge: Action start Falling edge: Resets outputs. If a falling edge occurs before the function block has completed its action, the outputs operate in the usual manner and are only reset if either the action is completed or in the event of an error. In this case, the corresponding output values (xDone, xError, iError) are present at the outputs for exactly one cycle. dtDateAndTime DT Output xDone BOOL Action successfully completed xBusy BOOL Function block active xError BOOL TRUE : error occurred, function block aborts action FALSE : no error eError ERROR Error description for diagnosis
Functions ¶ Utility Functions DTConcat (Function) DTSplit (Function) DateConcat (Function) DateSplit (Function) GetDayOfWeek (Function) TODConcat (Function) TODSplit (Function)
Utility Functions ¶ DTConcat (Function) DTSplit (Function) DateConcat (Function) DateSplit (Function) GetDayOfWeek (Function) TODConcat (Function) TODSplit (Function)
DTConcat (FUN) ¶ FUNCTION DTConcat : DATE_AND_TIME The function converts year, month, hour, minute and second to the IEC 6-1131-3 format DATE_AND_TIME . In case of invalid inputs DT#1970-01-01-00:00 will be returned. InOut: Scope Name Type Comment Return DTConcat DT Input uiYear UINT 1970 .. 2099 uiMonth UINT 1 .. 12 uiDay UINT 1 .. 31 uiHour UINT 0 .. 23 uiMinute UINT 0 .. 59 uiSecond UINT 0 .. 59 peError POINTER TO ERROR
DTSplit (FUN) ¶ FUNCTION DTSplit : ERROR The function provides year, month, hour, minute and second from the IEC 6-1131-3 format DATE_AND_TIME . InOut: Scope Name Type Comment Return DTSplit ERROR Input dtDateAndTime DT puiYear POINTER TO UINT 1970 .. 2099 puiMonth POINTER TO UINT 1 .. 12 puiDay POINTER TO UINT 1 .. 31 puiHour POINTER TO UINT 0 .. 23 puiMinute POINTER TO UINT 0 .. 59 puiSecond POINTER TO UINT 0 .. 59
DateConcat (FUN) ¶ FUNCTION DateConcat : DATE This function converts year, month and day to the IEC 6-1131-3 format DATE . In case of invalid entries D#1970-01-01 will be returned. InOut: Scope Name Type Comment Return DateConcat DATE Input uiYear UINT 1970 .. 2099 uiMonth UINT 1 .. 12 uiDay UINT 1 .. 31 peError POINTER TO ERROR
DateSplit (FUN) ¶ FUNCTION DateSplit : ERROR This function provides year, month and day from the IEC 6-1131-3 format DATE . InOut: Scope Name Type Comment Return DateSplit ERROR Input datDate DATE puiYear POINTER TO UINT 1970 .. 2099 puiMonth POINTER TO UINT 1 .. 12 puiDay POINTER TO UINT 1 .. 31
GetDayOfWeek (FUN) ¶ FUNCTION GetDayOfWeek : RTCLK.WEEKDAY This function determines the day of the week of a specified date. InOut: Scope Name Type Return GetDayOfWeek RTCLK.WEEKDAY Input dtDate DATE peError POINTER TO ERROR
