INTEGRAL

The INTEGRAL instruction integrates a real value during the defined cycle time.
  • When the INTEGRAL function block is first initialized, its initial values are not considered. Use the R1 parameter to set the initial values for a calculation.
  • To prevent the loss of the integrated value, the integration value is not cleared automatically when the controller transitions from
    Program
     to
    Run
     or when the Run parameter transitions from FALSE to TRUE. Use the R1 parameter to clear the integral value when first transitioning the controller from
    Program
     to
    Run
     mode and when starting a new integration.
  • We do not recommend using the optional EN or ENO parameters with this function block because the cycle time calculation becomes disrupted when EN is FALSE, resulting in an incorrect integration. If the EN or ENO parameters are used, toggle the R1 parameter with EN equal to TRUE to clear the current result and ensure correct integration.
  • Integration is performed with a time base of milliseconds (that is, integrating an input of 1 with an initial value of 0 for 1 second results in a value of 1000). To convert the output of the instruction to units of seconds, divide the output by 1000.
  • If the CYCLE parameter value is less than the cycle timing of the execution of the device, the sampling period is forced to the cycle timing.
  • XIN sampling and function block executions occur every cycle time + Scan Time Jitter.
  • For a given user program, Scan Time Jitter varies from controller to controller.
  • The cycle time determines the sensitivity of the Integral function block. Changes occurring in XIN between two samplings (or within the cycle time) are not taken into account when the integral XOUT value is calculated.
  • Cycle time and Scan Time Jitter both contribute to the overall inaccuracy of Integral output as shown in the XIN in sync with the function block execution example and the XIN not in sync with function block execution example.
Languages supported: Function block diagram, ladder diagram, structured text.
This instruction applies to the Micro810, L20E, L50E, and L70E controllers.
INTEGRAL
INTEGRAL
INTEGRAL parameters
Parameter
Parameter Type
Data Type
Description
RUN
Input
BOOL
Mode:
  • TRUE = integrate
  • FALSE = hold
R1
Input
BOOL
Overriding reset.
XIN
Input
REAL
Input: Any real value.
X0
Input
REAL
Initial value.
CYCLE
Input
TIME
Sampling period. Possible values range from 0ms through 49d17h2m47s294ms.
Q
Output
BOOL
Not R1.
XOUT
Output
REAL
Integrated output.

INTEGRAL examples

INTEGRAL function block diagram example
INTEGRAL function block diagram example
INTEGRAL ladder diagram example
INTEGRAL ladder diagram example
INTEGRAL structured text example
INTEGRAL structured text example
(* ST Equivalence: INTEGRAL1 is an instance of a INTEGRAL block *)

INTEGRAL1(manual_mode, NOT(manual_mode), sensor_value, init_value, t#100ms);

controlled_value := INTEGRAL1.XOUT;
Results
Results

XIN in sync with function block execution example

The following images show the effect of Scan Time Jitter on the XOUT value:
Effect of Scan Time Jitter on the XOUT value
Scan Time Jitter on the XOUT value
Scan Time Jitter on the XOUT value

XIN not in sync with function block execution example

The following images show an example in which an error is introduced in the XOUT value of an Integral function block:
Example where an error is introduced in the XOUT value of an Integral function block
Example where an error is introduced in the XOUT value of an Integral function block
Example where an error is introduced in the XOUT value of an Integral function block
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