You're reading the documentation for an older, but still supported version (1.33.4).
For information on the latest version, please have a look at 1.33.5.

MONITORING_CTRLIO_EX2

This structure provides the current state of the I/O installed in the controller’s Safety board (EX2). It aggregates input, output, and encoder sections, plus a reserved area.

BYTE#	Field Name	Data Type	Value	Remarks
0	_tInput	READ_CTRLIO_INPUT_EX2		I/O Information (#1): Digital/Analog/Switch/Safety/Analog-mode
48	_tOutput	READ_CTRLIO_OUTPUT_EX2		I/O Information (#2): Digital/Analog/Analog-mode
90	_tEncoder	READ_ENCODER_INPUT		I/O Information (#3): Encoder strobe/raw/reset
102	_szReserved	unsigned char[24]		Reserved Space (size: 24 B)

Total size: 126 bytes

Defined in: DRFS.h

typedef struct _MONITORING_CTRLIO_EX2
{
    READ_CTRLIO_INPUT_EX2  _tInput;     /* 48 bytes */
    READ_CTRLIO_OUTPUT_EX2 _tOutput;    /* 42 bytes */
    READ_ENCODER_INPUT     _tEncoder;   /* 12 bytes */
    unsigned char          _szReserved[24];
} MONITORING_CTRLIO_EX2, *LPMONITORING_CTRLIO_EX2;