FB_BA_LightGroupDaylight

This template represents a daylight-dependent light control that automatically switches on and off depending on occupancy. It is intended for corridors and passageways. An upstream, optimizing switch-on function FB_BA_LightCtrlValue ensures the specification of a light switch-on value that switches the downstream constant light regulation close to the desired setpoint. As soon as the light is switched on via occupancy, it is automatically readjusted according to the setpoint.

Function

In contrast to the FB_BA_LightGroupConstant template (constant light regulation), only the control mode of the function block FB_BA_LightCtrlConst is used here. It is not necessary to manually override the constant light regulation for corridors and passageways, which is why there is no switch input. If manual switch-on is nevertheless required, the switch should be treated as an occupancy sensor and not linked to the inputs bSwi, bSwiUp or bSwiDwn, as these trigger the override without control.

A rising edge at bPresence activates the function block and it is set directly to the switch-on value optimized by FB_BA_LightCtrlValue.

On a falling edge at the template input bPresence or by setting bResetRoomFunction, the light control block is disabled, whereby, if selected, it still announces its shutdown via a switch-off ramp with a dwell time at a pre-switch-off value. The function is then inactive and the output bControlMode is deleted.

In addition to the internal telegrams from LightEvent and OnValue (teach-in function), the input-side stAreaLighting and stScene are also routed to the selector (PrioSwi).

Here, stArea represents the resulting telegram from the higher levels (area, floor and building), while stScene is reserved for any lighting scene to override the constant light regulation.

The OnValue.stTeachLighting telegram is only active during the teach-in process of OnValue (FB_BA_LightCtrlValue).

The telegram selector (PrioSwi) forwards the telegram with the highest priority - with the same priority, the last telegram sent (last writer wins).

The setpoint for constant light regulation is set using an analog object SpBrightness.

Input stReferenceFeedback

Information about the controlled light actuator or the reference actuator of a group is fed back into the light control function via this input.

The light value of the reference actuator is of particular importance here: If the light actuator is already controlled by another function of the same or lower priority and the template described here now "takes over" control, it must control the actuator based on its existing light value.

The light preset block fOnValue also requires information on the current light value of the controlled group. Since it can only determine the increase in brightness itself, it can only specify the increase on the current light value - the absolute value is the sum of the current light value and the increase.

In addition, current values and states are transmitted and can be displayed via the HMI.

Data exchange HMI

The data exchange with the HMI is realized here in the base class FB_BA_Ext_LightBase (internal function block). The use of the following variables is visible in this template:

• bLightOn_Out: Output information "Light On" to the HMI.
• bErr_Out: Output information "Reference actuator faulty" to the HMI.
• eActualPrio_Out: Currently controlling telegram priority to the HMI.

The initialization of the template takes place within the method FB_Init.

Block diagram

Syntax

FUNCTION_BLOCK FB_BA_LightGroupDaylight EXTENDS FB_BA_Ext_LightBase
VAR_INPUT
  bResetRoomFunction     : BOOL;
  bPresence              : BOOL;
  bTeachOnValue          : BOOL;
  fBrightness            : REAL;
  stAreaLighting         : ST_BA_Lighting;
  stScene                : ST_BA_Lighting;
  stReferenceFeedback    : ST_BA_LightActuatorFeedback;
END_VAR

VAR_OUTPUT
  stLighting             : ST_BA_Lighting;
  bAdjusting             : BOOL;
END_VAR

VAR_INPUT CONSTANT PERSISTENT
  fHys                   : REAL;
  nRampTi                : UDINT;
  nPreOffRampTi          : UDINT;
  nBrtnsAdjTi            : UDINT;
  fPreOffVal             : REAL;
  nPreOffDly             : UDINT;
  fMinVal                : REAL;
  nMinOffDly             : UDINT;
  nMinOnDly              : UDINT;
  fLgtT                  : REAL;
END_VAR

VAR_INPUT CONSTANT
  SpBrightness           : FB_BA_AV_Op;
  OnValue                : FB_BA_LightCtrlValue := ( ePrio := E_BA_LightingPrio.eMaintenance);
  LightEvent             : FB_BA_LightingEvt := ( ePrio := E_BA_LightingPrio.eSimple);
END_VAR
VAR
  ConstLgtCtrl           : FB_BA_LightCtrlConst;
  PrioSwi                : FB_BA_LightingTgmSel4;
END_VAR