ProSoft Technology MVI56E-LDM User Manual
Page 122
CIP API Functions
ControlLogix Platform ♦ "C" Programmable
Developer's Manual
Linux Application Development Module
Page 116 of 264
ProSoft Technology, Inc.
March 12, 2014
OCXcip_SetTagDbOptions
Syntax
int OCXcip_SetTagDbOptions (OCXHANDLE apihandle,
OCXTAGDBHANDLE tdbHandle,
DWORD optFlags,
WORD structAlign);
Parameters
apihandle
handle returned by previous call to OCXcip_Open
TagDbHandle
Handle created by previous call to OCXcip_CreateTagDbHandle
optFlags
Bit masked option flags field. Multiple options may be combined (with)
OCX_CIP_TAGDOPT_NORM_STRINGS
:
Normalized strings are stored as
OCXcip_GetStructMbrInfo()
will report strings as having a datype of
OCX_CIP_TAGDB_DATYPE_NORM_STRING
. The report eleSize will be
the size of the string data buffer including space for the NULL term
(OCX_CIP_STRING82s will have an eleSize of 83). The reported
hStruct
will be zero(no a struct). When accessing normalized strings
(with OCXcip_AccessTagDataDb()), pass a daType of
PCX_CIP_TAGDB_DATYPE_NORM_STRING
.
OCX_CIP_TAGDBOPT_NORM_BOOLS
:
With this option, OCX_CIP_BOOL variables will be treated as bytes.
OCX_CIP_BYTE
, OCX_CIP_WORD, OCX_CIPDWORD, and
OCX_CIP_LWORD
types will be converted to arrays of OCX_CIP_BOOLs.
A normalized OCX_CIP_DWORD will be normalized to an array of 32
OCX_CIP_BOOL
(which will occupy 32 bytes) for example. When
accessing arrays of BOOKs (with OCXcip_AccessTagDataDb()), any
number of array elements may be specified - masked and unmasked
controller reads/writes will be executed as required to complete the tag
access. Some OCX_CIP_BOOLs cannot be normalized. The
FUNCTION_GENERATOR structure has OCX_CIP_BOOLs that are
aliased into an OCX_CIP_DINT. Since the DINT base member is not
expanded into a BOOL array, the BOOL alias structure members cannot
be normalized. A special (and rarely used) data type has been created to
identify alias structure member OCX_CIP_BOOLS that could not be
normalized: OCX_CIP_TAGDB_DATYPE_NORM_BITMASK.
OCX_CIP_TAGDBOPT_STRUCT_MBR_ORDER_NATIVE
: This option will
cause OCXcip_GetStructMbrInfo() to retrieve structure members in
native order (lowest offset to highest) instead of alphabetical order. This
is not a normalization option.
structAlign
Ignored if no normalization options are used. If normalization is enabled,
this may be 1, 2, 4, or 8 (4=recommended). Structure members will be
aligned according to the minimum alignment requirement. That is, if
structALign is 4, OCX_CIP_DINTs will be aligned on 4 byte boundaries,
but OCX_CIP_INTs will be aligned on 2 byte boundaries.