FB_LightControl
Function block for daylight-dependent lighting control with up to 30 interpolation points.
At the core of this function block is an input/control value table consisting of 30 elements with threshold switching. If the input value reaches the range of an interpolation point (arrControlTable[n].nActualValue-arrControlTable[n].nSwitchRange/2 ... arrControlTable[n].nActualValue+arrControlTable[n].nSwitchRange/2), the control value jumps to the corresponding function value arrControlTable[n].nSetpoint (see diagram). Coupled to this is a ramp block that runs up the control value over the time tRampTime.
When switching on with a positive edge at bOn, however, the light is initially switched directly to the nearest control value. Only then is the controller activated. While the control is active, "post-starting" can take place at any time with a positive edge at bOn, thus directly controlling the light to the nearest control value. A positive edge at bOff switches the light off directly.
The whole range of the table does not have to be used. The first table element (arrControlTable, see below) for which the parameter nSwitchrange is 0 is considered the start of the unused area.
VAR_INPUT
bEnable : BOOL;
bOn : BOOL;
bOff : BOOL;
nActualValue : UINT;
tRampTime : TIME := t#30s;
arrControlTable : ARRAY[1..30] OF ST_ControlTable;
nOptions : DWORD;
bEnable: The bOn and bOff inputs are active as long as this input is TRUE. A negative state deactivates the inputs.
bOn: A rising edge directly switches nLightLevel to the nearest control value.
bOff: A rising edge directly switches nLightLevel to "0".
nActualValue: Current brightness.
tRampTime: Time period during which the brightness value is controlled to the next control value. (Preset value: 30 s).
arrControlTable: Input value/control value table. arrControlTable[1] to arrControlTable[30] of type ST_ControlTable.
nOptions: Reserved for future developments.
VAR_OUTPUT
bLight : BOOL;
bBusy : BOOL;
bControlActive : BOOL;
bError : BOOL;
nErrorId : UDINT;
bLight: This output is set as long as nLightLevel is greater than "0".
bBusy: This output is always active as long as the processing of a command (bOn, bOff, bToggle or ramp) is active.
bControlActive: This output is active as long as the control is active.
bError: This output is switched to TRUE as soon as an error occurs during the execution of a command. The command-specific error code is contained in nErrorId. Is reset to FALSE by the execution of a command at the inputs.
nErrorId: Contains the specific error code of the most recently executed command. Is reset to "0" by the execution of a command at the inputs. See Error codes.
VAR_IN_OUT
nLightLevel : UINT;
nLightLevel: Output control value of the function block and reference to the light output value.
Requirements
Development environment | Required PLC library |
|---|---|
TwinCAT from v3.1.4020.32 | Tc2_BABasic from v3.1.0.0 |