Rockwell Automation 6008-SV2R VMEbus remote I/O Scanner - Manual (Page 141)

Chapter
Programming the Scanner
8
8Ć7
SCANLIST command
/*
**
** SCANLIST() –– configure a 6008–SV2 channel scan list
**
**
This function executes a SCANLIST command, using the scanlist provided by the
** caller in the scanlist_data parameter.
**
**
parameters: pointer to channel structure
** pointer to scanlist_data structure
** return values: –1 = unable to lock general data area semaphore
** –2 = did not get cmd–complete interrupt
** ELSE channel confirmation status word
**
*/
int
scanlist (channel far *chan, scanlist_data far *scancfg)
{
csa_data far *csa;
unsigned short res;
/* map channel & establish pointers */
map_channel(chan);
csa = (csa_data far *) chan–>ControlStatusArea;
/* get the semaphore */
if (lock_gda(chan) != 0) {
unmap_channel(chan);
fprintf(stdout, ”scanlist: lock aquire FAILED\n”);
return –1;
}
/* set up the control/status area */
csa–>cnfstat = 0x000F;
/* confirm status word */
csa–>cmd = CMD_SCANLIST; /* command word */
csa–>datalen = scancfg–>scanlist_len; /* length of data word */
/* copy the scan list to the general data area */
blockcpy(chan–>GeneralDataArea, scancfg–>scanlist,
(size_t) scancfg–>scanlist_len);
/* send the command interrupt */
assert_cmd(chan);
/* poll for command result */
if (wait_for_cmdcmpl(chan) == FALSE) {
/* clear the semaphore */
unlock_gda(chan);
unmap_channel(chan);
fprintf(stdout, ”scanlist: wait failure, lock cleared\n”);
return –2;
}
/* clear the semaphore & unmap the channel */
res = csa–>cnfstat;
unlock_gda(chan);
unmap_channel(chan);
return (int) res;
}