FB_ALY_SlopeAnalysis_1Ch
The Slope Analysis 1Ch calculates the slope between two values of the input stream. One of those two values is the current input value and the second value is the input value that occurred a defined number (configured by the parameter Num Values) of cycles before in the input stream. The difference between these two values is returned as Delta Value.
The corresponding distance on the time-coordinate is calculated as the difference of the timestamps of these two values and is provided as the output value Delta Time. Note that the value Delta Time is displayed in nanoseconds, but for the calculation of the slope it is scaled to a second as base unit.
The Slope is then calculated as the fraction of Delta Value and Delta Time (scaled to seconds) and estimates the gradient for the timestamp in the center of the two timestamps used in the calculation of Delta Time. This is the value returned as Time Slope if it corresponds to a timestamp of the input stream. For configurations, where Num Values is an uneven number there is no input value matching the exact centre timestamp. In this case the timestamp of the value that directly succeeded the calculated centre timestamp is returned as Time Slope.
Further, the algorithm provides the minimal slope, the maximal slope and the time values of minimum and maximum.
Syntax
Definition:
FUNCTION_BLOCK FB_ALY_SlopeAnalysis_1Ch
VAR_INPUT
bPersistent: BOOL;
END_VAR
VAR_OUTPUT
ipResultMessage: Tc3_EventLogger.I_TcMessage;
bError: BOOL;
bNewResult: BOOL;
bConfigured: BOOL;
fSlope: LREAL;
fSlopeMin: LREAL;
fSlopeMax: LREAL;
fDeltaValue: LREAL;
fbDeltaTime: FB_ALY_Timespan;
fbTimeSlope: FB_ALY_DateTime;
fbTimeSlopeMin: FB_ALY_DateTime;
fbTimeSlopeMax: FB_ALY_DateTime;
END_VAR
Inputs
Name | Type | Description |
|---|---|---|
bPersistent | BOOL | If the value is |
Outputs
Name | Type | Description |
|---|---|---|
ipResultMessage | Contains more detailed information on the current return value. This special interface pointer is internally secured so that it is always valid/assigned. | |
bError | BOOL | This output is |
bNewResult | BOOL | When a new result has been calculated, the output is |
bConfigured | BOOL | Displays |
fDeltaValue | LREAL | Difference of the values of the first and last element of the window. |
fbDeltaTime | FB_ALY_Timespan | Difference of timestamp values of the first and last element of the window. It is scaled to seconds. |
fSlope | LREAL | Division of fDeltaValue and fDeltaTime. |
fSlopeMin | LREAL | Minimum occurred value of fSlope. |
fSlopeMax | LREAL | Maximum occurred value of fSlope. |
fbTimeSlope | FB_ALY_DateTime | Timestamp of the calculated slope. It is placed in the center of the configured window. |
fbTimeSlopeMin | FB_ALY_DateTime | Timestamp of the last updated fSlopeMin. |
fbTimeSlopeMax | FB_ALY_DateTime | Timestamp of the last updated fSlopeMax. |
Methods
Name | Definition Location | Description |
|---|---|---|
Call() | Local | Method calculates the outputs for a given configuration. |
Configure() | Local | General configuration of the algorithm with its parameterized conditions. |
Reset() | Local | Resets all internal states or the calculations made so far. |
SetChannelValue() | Local | Method to pass values to the algorithm. |
Sample
VAR
fbSlopeAnalysis : FB_ALY_SlopeAnalysis_1Ch;
fbSystemTime : FB_ALY_GetSystemTime;
nNumValues : UDINT := 200;
bConfigure : BOOL := TRUE;
nInput : INT;
END_VAR
// Configure algorithm
IF bConfigure THEN
bConfigure := FALSE;
fbSlopeAnalysis.Configure(nNumValues);
END_IF
// Get current system time
fbSystemTime.Call();
// Call algorithm
fbSlopeAnalysis.SetChannelValue(nInput);
fbSlopeAnalysis.Call(fbSystemTime.tSystemTime);
Requirements
Development environment | Target platform | Plc libraries to include |
|---|---|---|
TwinCAT v3.1.4024.0 | PC or CX (x64, x86) | Tc3_Analytics |