Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Fri, 14 Jun 2013 10:43:29 -0500

Hi Vikram,

On 2013-06-14 Vikram Bhagat wrote:
> as i understand of i defiend VAL field to some value in DB file then it
>  sould be written on output. 
> I have develop my own driver to write value on serial port using asyn
>  driver. and it is working fine. 
> if i write some value . it is output on port.
>  
> But if i write VAL field in DB file.   it is not writting that value to the
>  output 

To write the record value to the port you have to arrange for the record to 
be processed.  You can do this in several different ways, but depending on 
your port driver not all of them will work.  The simplest is to set the PINI 
field of the record to YES, which will cause it to be processed automatically 
at IOC Initialization time.  However if your Asyn port has not connected up 
to the device in time that might not work, and in that case a better solution 
might be to put a command in your startup script to put the value at some 
time after the call to iocInit, like this:
    ...
    iocInit()
    epicsThreadSleep(2)
    dbpf TEST:VAL 7

The epicsThreadSleep command might not be necessary in some cases, or you 
might have to make the sleep delay longer according to how long it takes for 
your particular Asyn port to connect.

- Andrew
-- 
It is difficult to get a man to understand something, when his salary
depends upon his not understanding it. -- Upton Sinclair

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System