Converts data from the format for the given point type to the general toolkit format.
The Device Communications Toolkit calls user_write_data() to write to the same device domain from various points of different data types. The user_write_data() subroutine assumes data is in little endian format (least significant byte first) and is otherwise consistent with the data type of the device domain.
For example, an SINT (8 bit
integer) point can be configured in a bit domain and used to set
eight (8) bits at a time, or the individual bits can be set with
BOOL setpoints.
The Device Communications Toolkit calls user_cvt_data_to_device() for individual points to perform data conversion specific to the point data type.
For example, if the point data
type is not SINT (8 bit integer), it may be necessary to swap bytes
or swap words in the point data to make it little endian for
user_write_data().
You can find the template for this subroutine in:
usrtm_cvtto.c
Syntax
void user_cvt_data_to_device ( device_struct,
address_struct, element_cnt, element_size,
pnt_data_type, data_buffer)
DEVICE_DATA *device_struct;
ADDR_DATA *address_struct;
int element_cnt;
int element_size;
int pnt_data_type;
char *data_buffer;
Input Parameters
device_struct
Is a pointer to the structure defining device data. DEVICE_DATA is a typedef to a structure defined in <inc_path/toolkit.h>.
address_struct
Is a pointer to the address from which the data was read. ADDR_DATA is a typedef to a structure defined in <inc_path/toolkit.h>.
element_cnt
Is the number of point elements to convert.
element_size
Is the number of bytes per point element.
pnt_data_type
Is the CIMPLICITY point type. The standard CIMPLICITY point types supported by the Device Communications Toolkit are:
TOOLKIT_BOOLEAN
TOOLKIT_BITSTRING
TOOLKIT_OCTETSTRING
TOOLKIT_TEXTPOINT
TOOLKIT_UNSIGNED_ANALOG8
TOOLKIT_UNSIGNED_ANALOG16
TOOLKIT_UNSIGNED_ANALOG32
TOOLKIT_ANALOG8
TOOLKIT_ANALOG16
TOOLKIT_ANALOG32
TOOLKIT_FLOATINGPOINT
Output Parameters
data_buffer
Is the buffer of data to be converted.
Return Value
None.
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Device Communications toolkit subroutines. |
