Re: how to get the exect IOC time of event triggered

[Ralph Lange <Ralph.Lange@bessy.de>]

Hi Huang Song,

Your problem is based on a simple misunderstanding: The IOC timestamps 
are so closely related to the matching data, that for Channel Access 
timestamps are part of the data structure, not the event structure.

I.e., the void pointer dbr inside the event_handler_args points to the 
value, which is embedded in one of the many different DBR_... types - 
you will get your data in the DBR type that you specify when subscribing 
to a channel. If you subscribe requesting DBR_TIME_... data, you will 
get the timestamp and the related value in one structure that dbr points to.

Check the CA Reference Manual (under Channel Access Data Types) or 
db_access.h for the available types and their respective data structures.

Good luck!
Ralph


huangsong wrote:

> Hello, everyone
>
> I'm now programming using channel access client library. By CA Monitor, we can get the
> event messages after we use ca_add_masked_array_event() to register on some PVs.
>
> If there are some events triggered, we get messages which include things like:
> channel name
> pv values
> status
>
>
> But in the messages, I can't get the exact IOC time when it trigger the event. 
> The event_handler_args defined like this in cadef.h:
>
> typedef struct  event_handler_args{
>        void            *usr;   /* User argument supplied when event added      */
>        struct channel_in_use
>                        *chid;  /* Channel id                                   */
>        long            type;   /* the type of the value returned               */
>        long            count;  /* the element count of the item returned       */
>        READONLY void   *dbr;   /* Pointer to the value returned                */
>        int             status; /* ECA_XXX Status of the requested op from server       */
> }evargs;
>
>
> Is there any parameter including the exect time on IOC when the event triggered?
> I hope it should not be the responsibility of Event Handler routines.
>
>
> Best wishes and regards,
> Huang song
> IHEP
>
>                                         huangsong@ihep.ac.cn
> 					 2005.06.06
>