Rockwell-automation 1771-DMC_DMC1_DMC4_DXPS Control Coprocessor User M Manual do Utilizador descarregar pdf (Página 234)

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Appendix B

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B-103

w_rslt_mask

Bit map of the results from the requested write message instructions.

Bit 0 = message 0; bit 31 = message 31. If the bit is set, this message

has completed I/O or has timed out.

Returns

Status Symbolic Name Meaning



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Description

Use MSG_WAIT to wait for one or more asynchronous message

operations to complete. MSG_WAIT will check for the completion of any

combination of pending read/write message numbers. The message

numbers are encoded in a read and write mask. The corresponding

message entry is checked for I/O completion. If the message has

completed, the iostat entry for that message is updated and the

corresponding bit in the read/write result mask is set. If none of the

requested messages have completed I/O and the sync parameter is 0, this

function will return immediately to the caller (asynchronous).

Otherwise, this function will wait until at least one of the requested

messages has completed.

Important: If both r_mask and w_mask are 0 or if none of the messages

for which bits are set were requested, the calling process will wait forever

(only if sync=1).

C Example

@_sysedit: equ 1 /* Edition 1. */

@_sysattr: equ 0x8000 /* Revision 00 (re-entrant 0x80 << 8 + revision 00) */

#include <copro.h>

main ()

{

int read_var,write_var,one_shot,iostat,status;

unsigned rm,wm,ret_rm,ret_wm;

read_var = 1;

one_shot = 42;

CC_INIT(); /* initialize copro */

status = MSG_ZERO_MASK(&rm); /* clear out read and write masks */

status = MSG_ZERO_MASK(&wm);

status = MSG_SET_MASK(&rm,0); /* wait for read msg 0 & 1, write msg 1 */

status = MSG_SET_MASK(&rm,1);

status = MSG_SET_MASK(&wm,1);

/* post initial message handlers */

status = MSG_READ_HANDLER ( &one_shot, sizeof (one_shot), 1, 1, 45,

CC_LONG, PLC_WORD, &iostat);

status = MSG_READ_HANDLER ( &read_var, sizeof (read_var), 0, 1, 45,

CC_LONG, PLC_WORD, &iostat);

1 2 ... 229 230 231 232 233 234 235 236 237 238 239 ... 311 312

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