Rockwell Automation 1771-DMC_DMC1_DMC4_DXPS Control Coprocessor User Manual - Manual (Page 201)

API Library of Routines
Appendix B
DTL_RMW_W
B-70
Initiates an operation that reads a data element, modifies some of the bits,
then writes it back.
C Syntax
#include <copro.h>
unsigned DTL_RMW_W (name_id, and_mask, or_mask, iostat)
unsigned name_id;
unsigned and_mask;
unsigned or_mask;
unsigned *iostat;
Parameters
name_id
DTL_C_DEFINE returns this handle when the data item to be read and
modified is defined.
and_mask
Use the and_mask to specify the bits you want to preserve in the data
item. A “1” bit in the AND mask preserves the corresponding bit in the
data item; a “0” bit forces the corresponding bit to zero.
or_mask
Use or_mask to specify the bits you want to set in the data item.
A “1” bit in the OR mask forces the corresponding bit in the data item;
a “0” bit forces the corresponding bit unchanged. The OR mask is
applied after the AND mask.
iostat
Returns a final completion status. Possible completion status values are:
Value Meaning
0 DTL_SUCCESS = operation completed successfully
27 DTL_E_NOATMPT = I/O operation not attempted; see status variable for reason
41 DTL_E_CNVT = dataĆconversion error
xxx ¬ PCCC_E_xxx = operation refused by the PLCĆ5 programmable controller
¬ See Table B.A for PCCC errors.
DTL_RMW_W