This is the example enumerated data type ANALOG_SIGNAL_RANGE given in IEC 61131-3, defined as follows:

TYPE ANALOG_SIGNAL_RANGE :
   (BIPOLAR_10V, (* -10 to+10 VDC *)
    UNIPOLAR_10V, (* 0 to+10 VDC *)
    UNIPOLAR_1_5V, (* +1 to+5 VDC *)
    UNIPOLAR_0_5V, (* 0 to+5 VDC *)
    UNIPOLAR_4_20_MA, (* +4 to+20 mADC *)
    UNIPOLAR_0_20_MA) (* 0 to+20 mADC *)
    := UNIPOLAR_1_5V ;
END_TYPE

See the SEND_ENUMS/RCV_ENUMS Resource configurations for an example of the use and testing of an instance of this data type.