I am trying to define a sensor which will monitor displacement at a node. If the vertical displacement at this node exceeds 2.5m then the analysis should terminate. Y is vertical in my model. The lines from the input file are shown below. I am using Abaqus 2022 HF20. 

** stop analysis when U2 exceeds 2.5
*STEP CONTROL, NAME=StopOnU2, ACTION=END ANALYSIS
U2_Sensor, Max, 2.5
**

*OUTPUT, HISTORY, SENSOR, NAME=U2_Sensor
*NODE OUTPUT, Nset=sensor_carrier
U2,

**

Upon running the input file I get the following error message in the dat file. 

  *Step, name=Temperature, nlgeom=YES, inc=10000
 *dynamic, application=QUASI-STATIC, initial=NO
 *stepcontrol, name=STOPONU2, action=ENDANALYSIS

***ERROR: A REAL VALUE IS EXPECTED FOR THE LIMIT (CUTOFF) VALUE OF THE SENSOR 
          U2_SENSOR ON THE *STEP CONTROL.
***NOTE: DUE TO AN INPUT ERROR THE ANALYSIS PRE-PROCESSOR HAS BEEN UNABLE TO 
         INTERPRET SOME DATA.  SUBSEQUENT ERRORS MAY BE CAUSED BY THIS OMISSION

***ERROR: ONLY MIN, MAX, ABSMIN or ABSMAX CAN BE USED AS OPERATORS FOR THE 
          SENSOR U2_SENSOR ON  *STEP CONTROL.

Please advice if you notice any issues. Thanks