====== Time scheduler, integer ======

{{:en:mervis-ide:35-help:t19.png}}

===== Block name =====

T19_INT_SCHEDULER

===== ST call =====

<code st-iec>
PROGRAM TEST_T19
   VAR 
        FB : LIB.HVAC.V1_0.T19_INT_SCHEDULER := (TPGVALUE := [(STARTTIME := 0, STATE := 0),
     (STARTTIME := 1630, STATE := 7),
        (STARTTIME := 1750, STATE := 0),
        (STARTTIME := 3070, STATE := 7),
        (STARTTIME := 3190, STATE := 0),
        (STARTTIME := 65535, STATE := 0)], 
     EXCEPTIONS := [(STARTTIME := 1000, ENDTIME := 2000, STATE := 0)]);
      DT1:DT;
     INT1:UINT;
  END_VAR
 DT1:=getlocaltime();
    FB(CURRENTTIME:=DT1, OUT=> INT1);
END_PROGRAM
</code>

===== Library =====

LIB\HVAC

===== Version =====

V1.0

===== Description =====

Time scheduler is a source of an integer variable which value changes according to a weekly schedule with maximum 42 events (changes of state). Exception events (exceptions) defined by date, time, and state can be inserted.

The output value is recalculated at 30-second intervals.
===== Inputs =====

|Input       |Type|Description                                                                           |
|CURRENTTIME |DT  |Date and time in case that other date and time than system date and time shall be used|
|DEFAULTVALUE|UINT|Output value if en=false                                                              |

===== Outputs =====

|OUT|UINT|Current time schedule state|

===== Description of internal structures =====

|Description|Importance                           |
|STATE      |Current state of the time program    |
|STARTTIME  |Minutes from the beginning of the day|

===== Function =====

The time scheduler compares current date and time with the definition table and sends the actual state to the output. The output is a integer value. The possible scheduler states are defined The time scheduler can be edited from IDE or HMI - LCD display, web interface, touchscreen, SCADA or another client).

===== Application example =====

Time scheduler is used to specify variable setpoints in time directly. (Use [[en:mervis-ide:35-help:035-software_basic:060-libraries:040-hvac:020-time-programs:005-t17_boolean_scheduler|T17_BOOLEAN_SCHEDULER]] for boolean (on/off) output, and [[en:mervis-ide:35-help:035-software_basic:060-libraries:040-hvac:020-time-programs:025-t18_real_scheduler|T18_REAL_SCHEDULER]] for direct outout of analogue setpoints.) At the image below, T19 is used to switch between Off / Stage 1 / Stage 2 / CO<sub>2</sub> control modes.  In the CO<sub>2 </sub> mode, the fan stages are changed according to the  CO<sub>2</sub> concentration in the room. 

{{:en:mervis-ide:35-help:t19_example.png}}

In the editor there is a morning purge at 7:00 with Stage 2, Stage 1 is active in the morning and in the evening, while in the daytime the CO<sub>2</sub> control is active.

{{:en:mervis-ide:35-help:t19_example2.png}}