Rockwell Automation 1771-DMC_DMC1_DMC4_DXPS Control Coprocessor User Manual - Manual (Page 199)

API Library of Routines
Appendix B
DTL_READ_W_IDX
B-68
Returns
Status Symbolic Name Meaning
0 DTL_SUCCESS Operation successful
19 DTL_E_NOINIT DEFINE table not initialized
20 DTL_E_BADID Definition ID out of range
24 DTL_E_FAIL I/O completedwith errors
32 DTL_E_NODEF No such data item defined
157 CC_E_NOTCONNECT PLC is not connectedor offline
Description
Use the DTL_READ_W_IDX function to read a file, one element at a
time, from a PLC-5 programmable controller that is directly connected to
the control coprocessor.
This function is synchronous. When this function is initiated, your
C application programs stops until the function completes or fails.
For this function to be successful, the data definition must specify the
address to the first element of the file and the number of data items
must be 1.
You can address structured data types to either the structure level or the
element level. When you address to the structure level, the data type must
be RAW.
Valid Definition Examples
DTL_C_DEFINE (&idl, “N34:0”) /* specified to element 0,
default 1 item */
DTL_C_DEFINE (&idl, “T4:0.pre”) /* index 0 accesses T4:0.pre; index 14
accesses T4:14.pre */
DTL_C_DEFINE (&idl, “T4:0,1,raw”) /* index 0 accesses all three elements of
T4:0 (control, preset, accumulator);
index 14 access all three elements
of T4:14 (control, preset, accumulator)*/
Invalid Definition Example
DTL_C_DEFINE (&idl, “N34:3”) /* not specified to element 0 */
DTL_C_DEFINE (&idl, “N34:0,3,long”) /* number of items not 1 */