Table of Contents

Time scheduler integer, basic

Block name

T19_INT_SCHEDULER_BASE

ST call

PROGRAM TEST_T19_BASE
  VAR 
        FB : LIB.HVAC.V1_1.T19_INT_SCHEDULER_BASE := (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)]);
     DT1:DT;
     INT1:UINT;
  END_VAR
     DT1:=getlocaltime();
    FB(CURRENTTIME:=DT1, OUT=> INT1);
END_PROGRAM

Library

LIB\HVAC

Version

V1.1

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). This scheduler doesn't  support exceptions. Exceptions are implemented in T19_INTEGER_SCHEDULER.

The output value is recalculated at 30-second intervals.

Inputs

Input TypeDescription
CURRENTTIME DT Date and time in case that other date and time than system date and time shall be used
DEFAULTVALUEUINTOutput value if en=false

Outputs

OUTUINTCurrent time schedule state

Description of internal structures

DescriptionImportance
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 T17_BOOLEAN_SCHEDULER for boolean (on/off) output, and T18_REAL_SCHEDULER for direct outout of analogue setpoints.) At the image below, T19 is used to switch between Off / Stage 1 / Stage 2 / CO2 control modes.  In the CO2  mode, the fan stages are changed according to the  CO2 concentration in the room. 

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 CO2 control is active.