Rockwell Automation 1771-DMC_DMC1_DMC4_DXPS Control Coprocessor User Manual - Manual (Page 242)

API Library of Routines
Appendix B
MSG_WRITE_W_HANDLER
B-111
Returns
Status Symbolic Name Meaning
0 CC_SUCCESS Operation successful
124 CC_E_FAIL I/O completed with errors
133 CC_E_BAD_MSGID Message ID out of range
157 CC_E_NOTCONNECT PLC is not connected or offline
160 CC_E_INV_TO Invalid timeout value
162 CC_E_INV_CTYPE Invalid coprocessor data type
163 CC_E_INV_PTYPE Invalid PLCĆ5 data type
181 CC_E_MSGPEND Message already pending
182 CC_E_MSG_ABORT Message aborted
190 CC_E_SIZE Invalid size for operation
191 CC_E_TOOSMALL Size of buffer too small
Description
Use the MSG_WRITE_W_HANDLER function to initiate the processing
of unsolicited message-write instructions from the PLC-5 programmable
controller. This function puts an entry in the Message Control Table
(MCT) for the requested message number (0-31). When the PLC-5
programmable controller executes that message number, data from the
PLC-5 programmable controller is transferred to the specified user buffer.
This function is synchronous. When this function is initiated, the
application program stops until the function completes or fails. For the
asynchronous version of this command, see MSG_WRITE_HANDLER.
C Example
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short variable [4] /* buffer to receive write data */
unsigned timeout = 45; /* 45 second timeout */
unsigned msgnum = 10; /* plc message number 10 */
unsigned cc_type = 3; /* CC_WORD = 3; */
unsigned plc_type = 3; /* PLC_WORD = 3; */
unsigned items = 4; /* 4 words of data to be written by PLC-5 */
int iostat; /* iostatus return value */
int rtn_val; /* function return value */
rtn_val = MSG_WRITE_W_HANDLER (&variable, sizeof (variable), msgnum, items,
timeout, cc_type, PLC_type, &iostat);
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