FB_BA_LightGroupSwitch

One or more light actuators are combined in a light zone for simultaneous control, depending on local conditions.

This template represents a light zone (room) which is only operated via switches.

Function

The light can be switched on and off alternately via the template input bManualSwitch using the control block LightSwitch or dimmed up and down with a long button press (t > SwiOvrTi).

The inputs bOn and bOff allow the light to be switched on and off selectively, while the light value fSetLightValueMan_In is set directly via a HMI using the bSetLightValueMan_In command.

Switched by manual commands (not presence), the light function block FB_BA_LightCtrl normally works in such a way that it is always active and indicates this at the output bManualMode. This is due to the fact that the user may want to switch off the light in a targeted manner and this must not lead to a situation where the function block becomes inactive and a lower priority light telegram switches the actuators.

Normally, a falling edge at presence input bPrc deactivates the function. As this is not possible without presence detection, the light function is preceded by a logic that sends a trigger pulse to the reset input bRst when 0% is reached at the light output and thus deactivates the light control input anyway. Alternatively, deactivation can also be carried out via the template input bResetRoomFunction.

If the light is switched on, the function block LightEvent is activated by bManualMode = TRUE and a light telegram with the set light value is output.

In addition to the internal telegram from LightEvent, the input-side telegrams stAreaLighting and stScene are also routed to a 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 telegram selector (PrioSwi) forwards the telegram with the highest priority - with the same priority, the last telegram sent (last writer wins).

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.

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_LightCtrl (internal function block). The use of the following variables is visible in this template:

• fSetLightValueMan_In: Light value to be set via the HMI.
• bSetLightValueMan_In: Command from the HMI that the above light value is to be set.
• bLightOn_Out: Output information "Light On" to the HMI.
• fLightValue_Out: Output information light value 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_LightGroupSwitch EXTENDS FB_BA_Ext_LightCtrl
VAR_INPUT
  bManualSwitch           : BOOL;
  bOn                     : BOOL;
  bOff                    : BOOL;
  bResetRoomFunction      : BOOL;
  stAreaLighting          : ST_BA_Lighting;
  stScene                 : ST_BA_Lighting;
  stReferenceFeedback     : ST_BA_LightActuatorFeedback;
END_VAR
VAR_OUTPUT
  stLighting              : ST_BA_Lighting;
END_VAR
VAR_INPUT CONSTANT PERSISTENT
  nSwiOvrTi               : UDINT;
  nSwiTi                  : UDINT;
  nDimTi                  : UDINT;
  nPreOffRampTi           : UDINT;
  fOnVal                  : REAL;
  fPreOffVal              : REAL;
  nPreOffDly              : UDINT;
  bMemoryMode             : BOOL;
  eLightActivationMode    : E_BA_LightActivationMode;
  fLgtT                   : REAL;
END_VAR
VAR_INPUT CONSTANT
  LightEvent              : FB_BA_LightingEvt :=( ePrio:= E_BA_LightingPrio.eSimple);
END_VAR
VAR
  LightSwitch             : FB_BA_LightCtrl;
  PrioSwi                 : FB_BA_LightingTgmSel4;
  rtZero                  : R_TRIG;
  bRst                    : BOOL;
END_VAR