FB_ALY_TrendLine

The Trend Line function block provides for the forwarding of trends of the input signals for later use in the HMI dashboard. Any channels can be selected for forwarding; the number of channels can be controlled via NumChannels. One value per minute is then stored for each channel. This means that the function block is not suitable for signal forwarding, but rather for displaying trends for signals that change slowly.

Since the function of this function block is irrelevant for the analysis itself, it belongs to the Visualization Only category.

Syntax

Definition:

FUNCTION_BLOCK FB_ALY_StateHistogram_1Ch
VAR_OUTPUT
    ipResultMessage: Tc3_EventLogger.I_TcMessage;
    bError: BOOL;
    bNewResult: BOOL;
    bConfigured: BOOL;
    fbLastValue: FB_ALY_DateTime;
    nCountValues: ULINT;
END_VAR

Outputs

Name	Type	Description
ipResultMessage	I_TcMessage	Contains more detailed information on the current return value. For this special interface pointer, it is ensured internally that it is always valid/assigned.
bError	BOOL	The output is `TRUE` if an error occurs.
bNewResult	BOOL	When a new result has been calculated, the output is `TRUE.`
bConfigured	BOOL	Displays `TRUE` when the function block is successfully configured.
fbLastValue	FB_ALY_DateTime	Timestamp of the last data point added.
nCountValues	ULINT	Number of valid values.

Methods

Name	Definition location	Description
Call()	Local	Method for calculating the outputs for a specific configuration.
GetChannelOutputArray()	Local	Getting the result array of a channel without adding new values.
Reset()	Local	Resets all internal states or the calculations performed so far.
SetChannelInitial()	Local	Initialization of the initial values of a channel, for example with persistent data.
SetChannelValue()	Local	Method for passing values to the algorithm.
SetInital()	Local	Initialization of internal states, for example with persistent data.

Sample

VAR
    fbTrendLine : FB_ALY_TrendLine(nNumChannels := 2);
    fbSystemTime : FB_ALY_GetSystemTime;

    fInput1 : LREAL;
    nInput2 : ULINT;
END_VAR
VAR PERSISTENT
    aTrends : ARRAY[1..2] OF ARRAY[1..10080] OF LREAL;
    tLastValue : ULINT;
    nCountValues : UDINT;
END_VAR

// Get current system time
fbSystemTime.Call();

IF bSetPersistent THEN
    bSetPersistent := FALSE;
    fbTrendLine.SetChannelInitial(1, ADR(aTrends[1]), SIZEOF(aTrends[1]));
    fbTrendLine.SetChannelInitial(2, ADR(aTrends[2]), SIZEOF(aTrends[2]));
    fbTrendLine.SetInitial(tLastValue, nCountValues);
END_IF

// Call algorithm
fbTrendLine.SetChannelValue(1, fInput1);
fbTrendLine.SetChannelValue(2, nInput2);
fbTrendLine.Call(fbSystemTime.tSystemTime);
fbTrendLine.GetChannelOutputArray(1, ADR(aTrends[1]), SIZEOF(aTrends[1]));
fbTrendLine.GetChannelOutputArray(2, ADR(aTrends[2]), SIZEOF(aTrends[2]));
tLastValue := fbTrendLine.fbLastValue.nRaw;
nCountValues := fbTrendLine.nCountValues;

Requirements

Development environment	Target platform	Plc libraries to include
TwinCAT v3.1.4024.0	PC or CX (x64, x86)	Tc3_Analytics

Further Information