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Alarm filter changes by Bernd Schoeneburg

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Algorithm by Eric Norum.
Developed at the 2009 EPICS Codeathon.
This commit is contained in:
Andrew Johnson
2010-01-06 16:05:49 -06:00
parent 037e5f6a9d
commit 0af48f5a29
2 changed files with 110 additions and 40 deletions
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140
src/std/rec/aiRecord.c
View File

@@ -41,6 +41,9 @@
#undef GEN_SIZE_OFFSET
#include "epicsExport.h"
/* Hysterisis for alarm filtering: 1-1/e */
#define THRESHOLD 0.6321
/* Create RSET - Record Support Entry Table*/
#define report NULL
#define initialize NULL
@@ -99,7 +102,7 @@ typedef struct aidset { /* analog input dset */
extern unsigned int gts_trigger_counter;
*/
static void checkAlarms(aiRecord *prec);
static void checkAlarms(aiRecord *prec, epicsTimeStamp *lastTime);
static void convert(aiRecord *prec);
static void monitor(aiRecord *prec);
static long readValue(aiRecord *prec);
@@ -158,12 +161,15 @@ static long process(void *precord)
aidset *pdset = (aidset *)(prec->dset);
long status;
unsigned char pact=prec->pact;
epicsTimeStamp timeLast;
if( (pdset==NULL) || (pdset->read_ai==NULL) ) {
prec->pact=TRUE;
recGblRecordError(S_dev_missingSup,(void *)prec,"read_ai");
return(S_dev_missingSup);
}
timeLast = prec->time;
status=readValue(prec); /* read the new value */
/* check if device support set pact */
if ( !pact && prec->pact ) return(0);
@@ -174,7 +180,7 @@ static long process(void *precord)
else if (status==2) status=0;
/* check for alarms */
checkAlarms(prec);
checkAlarms(prec,&timeLast);
/* check event list */
monitor(prec);
/* process the forward scan link record */
@@ -305,60 +311,114 @@ static long get_alarm_double(DBADDR *paddr,struct dbr_alDouble *pad)
return(0);
}
static void checkAlarms(aiRecord *prec)
static void checkAlarms(aiRecord *prec, epicsTimeStamp *lastTime)
{
double val, hyst, lalm;
double alev;
enum {
range_Lolo = 1,
range_Low,
range_Normal,
range_High,
range_Hihi
} alarmRange;
static const epicsEnum16 range_stat[] = {
SOFT_ALARM, LOLO_ALARM, LOW_ALARM,
NO_ALARM, HIGH_ALARM, HIHI_ALARM
};
double val, hyst, lalm, alev, aftc, afvl;
epicsEnum16 asev;
if (prec->udf) {
recGblSetSevr(prec, UDF_ALARM, INVALID_ALARM);
prec->afvl = 0;
return;
}
val = prec->val;
val = prec->val;
hyst = prec->hyst;
lalm = prec->lalm;
/* alarm condition hihi */
asev = prec->hhsv;
alev = prec->hihi;
if (asev && (val >= alev || ((lalm == alev) && (val >= alev - hyst)))) {
if (recGblSetSevr(prec, HIHI_ALARM, asev))
prec->lalm = alev;
return;
/* check VAL against alarm limits */
if ((asev = prec->hhsv) &&
(val >= (alev = prec->hihi) ||
((lalm == alev) && (val >= alev - hyst))))
alarmRange = range_Hihi;
else
if ((asev = prec->llsv) &&
(val <= (alev = prec->lolo) ||
((lalm == alev) && (val <= alev + hyst))))
alarmRange = range_Lolo;
else
if ((asev = prec->hsv) &&
(val >= (alev = prec->high) ||
((lalm == alev) && (val >= alev - hyst))))
alarmRange = range_High;
else
if ((asev = prec->lsv) &&
(val <= (alev = prec->low) ||
((lalm == alev) && (val <= alev + hyst))))
alarmRange = range_Low;
else {
alev = val;
asev = NO_ALARM;
alarmRange = range_Normal;
}
/* alarm condition lolo */
asev = prec->llsv;
alev = prec->lolo;
if (asev && (val <= alev || ((lalm == alev) && (val <= alev + hyst)))) {
if (recGblSetSevr(prec, LOLO_ALARM, asev))
prec->lalm = alev;
return;
}
aftc = prec->aftc;
afvl = 0;
/* alarm condition high */
asev = prec->hsv;
alev = prec->high;
if (asev && (val >= alev || ((lalm == alev) && (val >= alev - hyst)))) {
if (recGblSetSevr(prec, HIGH_ALARM, asev))
prec->lalm = alev;
return;
}
if (aftc > 0) {
/* Apply level filtering */
afvl = prec->afvl;
if (afvl == 0) {
afvl = (double)alarmRange;
} else {
double t = epicsTimeDiffInSeconds(&prec->time, lastTime);
double alpha = aftc / (t + aftc);
/* alarm condition low */
asev = prec->lsv;
alev = prec->low;
if (asev && (val <= alev || ((lalm == alev) && (val <= alev + hyst)))) {
if (recGblSetSevr(prec, LOW_ALARM, asev))
prec->lalm = alev;
return;
}
/* The sign of afvl indicates whether the result should be
* rounded up or down. This gives the filter hysteresis.
* If afvl > 0 the floor() function rounds to a lower alarm
* level, otherwise to a higher.
*/
afvl = alpha * afvl +
((afvl > 0) ? (1 - alpha) : (alpha - 1)) * alarmRange;
if (afvl - floor(afvl) > THRESHOLD)
afvl = -afvl; /* reverse rounding */
/* we get here only if val is out of alarm by at least hyst */
prec->lalm = val;
return;
alarmRange = abs((int)floor(afvl));
switch (alarmRange) {
case range_Hihi:
asev = prec->hhsv;
alev = prec->hihi;
break;
case range_High:
asev = prec->hsv;
alev = prec->high;
break;
case range_Normal:
asev = NO_ALARM;
break;
case range_Low:
asev = prec->lsv;
alev = prec->low;
break;
case range_Lolo:
asev = prec->llsv;
alev = prec->lolo;
break;
}
}
}
prec->afvl = afvl;
if (asev) {
/* Report alarm condition, store LALM for future HYST calculations */
if (recGblSetSevr(prec, range_stat[alarmRange], asev))
prec->lalm = alev;
} else {
/* No alarm condition, reset LALM */
prec->lalm = val;
}
}
static void convert(aiRecord *prec)

10
src/std/rec/aiRecord.dbd
View File

@@ -138,6 +138,11 @@ recordtype(ai) {
promptgroup(GUI_ALARMS)
interest(1)
}
field(AFTC,DBF_DOUBLE) {
prompt("Alarm Filter Time Constant")
promptgroup(GUI_ALARMS)
interest(1)
}
field(ADEL,DBF_DOUBLE) {
prompt("Archive Deadband")
promptgroup(GUI_DISPLAY)
@@ -153,6 +158,11 @@ recordtype(ai) {
special(SPC_NOMOD)
interest(3)
}
field(AFVL,DBF_DOUBLE) {
prompt("Alarm Filter Value")
special(SPC_NOMOD)
interest(3)
}
field(ALST,DBF_DOUBLE) {
prompt("Last Value Archived")
special(SPC_NOMOD)