Technical data
Drive functions   
7.3 Function modules 
  Function Manual 
314  Function Manual, 06/2012, 6SL3097-4AB10-0BP4 
7.3.8.23  INT (integrator) 
Brief description 
●  Function block with integrating action 
●  Integrator functions: 
–  Set initial value. 
–  Adjustable integral time constant 
–  Adjustable limits 
–  For normal integrator operation, a positive limit value must be specified for LU and a 
negative limit value for LL. 
Mode of operation 
The change in output variable Y is proportional to input variable X and inversely proportional 
to the integral time constant TI. 
Output Y of the integrator can be limited via the inputs LU and LL. If the output reaches one 
of the two limits, a signal is sent via the outputs QU or QL. If LL ≥ LU, then output Y = LU. 
The discrete values (TA is the configured sampling time of the function block) are calculated 
according to the following algorithm: 
Yn = Yn-1 + (TA/TI) Xn
Y
n
  Value of Y in sampling time n 
Y
n-1
  Value of Y in sampling time n-1 
X
n
  Value of X in sampling time n 
When S = 1, the output variable Y is set to the setting value SV. Two functions can be 
performed via S: 
●  Track integrator (Y = SV) 
The digital input is S = 1 and the setting value SV is changed. If applicable, the output 
makes a jump to the setting value immediately after the setting operation. 
●  Set integrator to initial value SV. 
S is switched to 1. S is then set to 0, and the integrator starts from SV in the direction 
specified by the polarity of input variable X. 
Note 
TI is limited internally: TI = TA 










