struct epicsPV_s {
    chid channel;
    union {
        void* data;
        struct dbr_time_char* CHAR;
        struct dbr_time_short* SHORT;
        struct dbr_time_long* LONG;
        struct dbr_time_float* FLOAT;
        struct dbr_time_double* DOUBLE;
        struct dbr_time_enum* ENUM;
        struct dbr_time_string* STRING;
    };
    union {
        void* info;
        struct dbr_ctrl_char* info_CHAR;
        struct dbr_ctrl_short* info_SHORT;
        struct dbr_ctrl_long* info_LONG;
        struct dbr_ctrl_float* info_FLOAT;
        struct dbr_ctrl_double* info_DOUBLE;
        struct dbr_ctrl_enum* info_ENUM;
    };
    const char* units;
    int precision;
    caDatatype usedDatatype;
    caDatatype requestedDatatype;
    int status;
    char stringrep[40];
    PVconnectionCallback connectionCallback;
    void* userarg;
};

/* don't use cagetList directly, use caget */
int cagetList(double timeoutSec, epicsPV pv1, ...);

extern const char* PVdataTypeStrings[9];
extern const char* PVconnectionStateStrings [4];

#define PV_WITHUNITS 1