Hi all,
I want to process Modbus format data, but it's not going very smoothly.
My record file content is as follows:
record(waveform, "Sensor:waveform")
{
field(DESC, "read data")
field(DTYP, "stream")
field(NELM, "40")
field(FTVL, "UCHAR")
field(INP, "@RS485Test.proto getData SI")
field(SCAN, "5 second")
field(FLNK, "ProcessSensorData")
}
record(aSub, "ProcessSensorData")
{
field(INAM, "init_dose")
field(SNAM, "dose")
field(INPA, "Sensor:waveform NPP NMS")
field(FTVE, "DOUBLE")
field(OUTA, "Sensor:ai NPP NMS")
field(NOVA, "1")
}
record(ai, "Sensor:ai")
{
field(DESC, "Dose Measurement")
field(INP, "ProcessSensorData.VALA NPP NMS")
field(PREC, "3")
field(EGU, "µSv/h")
field(SCAN, "Passive")
}
dose.c:
#include <epicsExport.h>
#include <aSubRecord.h>
#include <registryFunction.h>
int init_dose(struct aSubRecord *psub) {
double *p1 = (double *)psub->vala;
*p1 = 0;
return 0;
}
int dose(struct aSubRecord *psub) {
char *inData;
double *pout1, doseRate;
unsigned char readData[4] = {0};
inData = (char *)psub->a;
pout1 = (double *)psub->vala;
//
For example, the returned data is: 01 04 0c 14 7b 3e 2e 00 03 00 00 00 00 00 00 ad c9. '14 7b' represents the low byte, and '3e 2e' represents the high byte.
readData[0] = inData[4];
readData[1] = inData[3];
readData[2] = inData[6];
readData[3] = inData[5];
doseRate = *((float*)readData);
*pout1 = doseRate;
return 0;
}
epicsRegisterFunction(init_dose);
epicsRegisterFunction(dose);
I used caget to observe Sensor:ai, and the result is always:
Sensor:ai 2.20405e-38
I think I made a mistake in my processing function, so I wrote a simple test program as follows:
#include <epicsExport.h>
#include <aSubRecord.h>
#include <registryFunction.h>
int init_dose(struct aSubRecord *psub) {
double *p1 = (double *)psub->vala;
*p1 = 0;
return 0;
}
int dose(struct aSubRecord *psub) {
char *inData;
double *pout1, doseRate;
inData = (char *)psub->a;
pout1 = (double *)psub->vala;
doseRate = inData[3]*0.1;
*pout1 = doseRate;
return 0;
}
epicsRegisterFunction(init_dose);
epicsRegisterFunction(dose);
However, the result is always:
Sensor:ai 0
What should I modify? Please help me.
