EPICS自定义设备支持--longin记录的设备支持编写

以下详细描述了一个longin记录设备支持模块编写过程以及用于测试这个模块的IOC的操作步骤：

1）创建一个目录lidriver用于保存这个IOC目录结构：

orangepi@orangepi4-lts:~/epics$ mkdir lidriver
orangepi@orangepi4-lts:~/epics$ ls
example  lidriver

2） 进入上一步创建的目录，并且使用makeBaseApp.pl脚本创建这个IOC应用程序目录结构和启动目录：

orangepi@orangepi4-lts:~/epics/lidriver$ makeBaseApp.pl -t ioc lidriver
orangepi@orangepi4-lts:~/epics/lidriver$ makeBaseApp.pl -i -t ioc lidriver
Using target architecture linux-aarch64 (only one available)
The following applications are available:lidriver
What application should the IOC(s) boot?
The default uses the IOC's name, even if not listed above.
Application name?
orangepi@orangepi4-lts:~/epics/lidriver$ ls
configure  iocBoot  lidriverApp  Makefile

3） 进入lidriverApp/src目录，编写设备支持源文件以及对应的支持文件，并且编辑对应目录下的Makefile文件：

a) devLiRnd.c

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <math.h>#include "alarm.h"
#include "dbDefs.h"
#include "dbAccess.h"
#include "recGbl.h"
#include "devSup.h"
#include "longinRecord.h"
#include "epicsExport.h"typedef struct devData{int upper_limit;int lower_limit;
}devData;static int lirand(devData * data)
{int ret;int mid = data->upper_limit - data->lower_limit + 1;ret = rand() % mid + data->lower_limit;return ret;
}
/* Create the dset for devLiRnd */
static long init_record(dbCommon *pcommon);
static long read_longin(longinRecord *prec);longindset devLiRnd = {{5, NULL, NULL, init_record, NULL},read_longin
};
epicsExportAddress(dset, devLiRnd);static long init_record(dbCommon *pcommon)
{longinRecord *prec = (longinRecord *)pcommon;devData * data;if (prec->inp.type != CONSTANT){recGblRecordError(S_db_badField, prec, "devLiRnd(init_record)illegal INP INP field");return S_db_badField;}data =(devData *)malloc(sizeof(devData));if (fabs(prec->hihi) < 1e-5){data->upper_limit = 100;}else{data->upper_limit = (int) prec->hihi;}if (fabs(prec->lolo) < 1e-5){data->lower_limit = 0;}else{data->lower_limit = (int)prec->lolo;}srand((unsigned int)time(NULL));prec->dpvt = (void *)data;return 0;
}static long readLocked(struct link *pinp, void *dummy)
{longinRecord *prec = (longinRecord *) pinp->precord;long status = 0;devData * data =(devData *) prec->dpvt;prec->val = lirand(data);if (dbLinkIsConstant(&prec->tsel) &&prec->tse == epicsTimeEventDeviceTime)dbGetTimeStamp(pinp, &prec->time);return status;
}static long read_longin(longinRecord *prec)
{long status = dbLinkDoLocked(&prec->inp, readLocked, NULL);if (status == S_db_noLSET)status = readLocked(&prec->inp, NULL);return status;
}

b） devLiRnd.dbd

device(longin, CONSTANT, devLiRnd, "random")

c) 将以上两个文件名添加到相同目录下的Makefile文件中：

...lidriver_DBD += devLiRnd.dbdlidriver_SRCS += devLiRnd.c...

4）在idriverApp/Db文件下，增加一个数据库实例文件longintest.db，并且编辑此路径下的Makefile文件：

a）longintest.db

record(longin, "$(P):LiRandom1")
{field(DESC, "Random Test")field(DTYP, "random")field(INP,  "1")field(HIHI, "50")field(LOLO, "0")field(SCAN, "1 second")
}record(longin, "$(P):LiRandom2")
{field(DESC, "Random Test")field(DTYP, "random")field(INP,  "1")field(HIHI, "100")field(LOLO, "51")field(SCAN, "1 second")
}

b) 将上面的文件名添加到Makefile中：

DB += longintest.db

5) 回到这个IOC的顶层目录lidriver ，执行make进行编译。

6）进入启动目录iocBoot/ioclidriver，编译启动脚本st.cmd：

#!../../bin/linux-aarch64/lidriver#- You may have to change lidriver to something else
#- everywhere it appears in this file< envPathscd "${TOP}"## Register all support components
dbLoadDatabase "dbd/lidriver.dbd"
lidriver_registerRecordDeviceDriver pdbbase## Load record instances
dbLoadRecords("db/longintest.db","P=Test")cd "${TOP}/iocBoot/${IOC}"
iocInit

7）启动这个IOC，用dbl查看加载的记录实例：

orangepi@orangepi5:/usr/local/EPICS/program/lidriver/iocBoot/ioclidriver$ ../../bin/linux-aarch64/lidriver st.cmd
#!../../bin/linux-aarch64/lidriver
< envPaths
...
############################################################################
iocRun: All initialization complete
## Start any sequence programs
#seq sncxxx,"user=orangepi"
epics> dbl
Test:LiRandom1
Test:LiRandom2
epics>

8) 用通道访问命令camonitor查看以上两个记录实例的值：

orangepi@orangepi4-lts:~$ camonitor Test:LiRandom1 Test:LiRandom2
Test:LiRandom1                 2023-08-28 11:15:43.229290 32
Test:LiRandom2                 2023-08-28 11:15:43.229302 61
Test:LiRandom1                 2023-08-28 11:15:44.229311 6
Test:LiRandom2                 2023-08-28 11:15:44.229398 57
Test:LiRandom1                 2023-08-28 11:15:45.229424 13
Test:LiRandom2                 2023-08-28 11:15:45.229458 75
....

实录实例Test:LiRandom1和Test:LiRandom2的值每秒钟随机变化一次，Test:LiRandom1的变化范围在0~50，而Test:LiRandom2的变化范围为51-100。