You're reading the documentation for an older, but still supported version (GL013300).
For information on the latest version, please have a look at GL013301.

MACHINE_TENDING_FOCAS_DISCONNECT

This structure defines the disconnection command and response for FOCAS communication. It includes the error code and connection handle used to close the active FOCAS session.

BYTE#	Field Name	Data Type	Value	Remarks
0	_ErrorCode	short		Disconnection error code (0 indicates success)
2	_hHandle	unsigned short		Connection handle identifier used to close FOCAS communication

Total size: 4 bytes

Defined in: DRFS.h

typedef struct _MACHINE_TENDING_FOCAS_DISCONNECT
{
    short          _ErrorCode;   /* 0: success, non-zero: error */
    unsigned short _hHandle;     /* FOCAS connection handle */
} MACHINE_TENDING_FOCAS_DISCONNECT, *LPMACHINE_TENDING_FOCAS_DISCONNECT;