RE: Asyn - max addresses per port

[Mark Rivers <rivers@cars.uchicago.edu>]

If you have maxAddress=N there is nowhere that you tell asynManager the value of N.  It allocates storage for device M when it is first referenced.  So you could have a single address of 10000 and that does not use any more memory than having a single address of 1.

However, asynPortDriver does require you to specify the value of N because it create N parameter table arrays in the constructor.  In the future asynPortDriver could be changed to use an std::map to map address to parameter table and then it could also allocate on-demand.

Mark


> -----Original Message-----
> From: tech-talk-bounces@aps.anl.gov [mailto:tech-talk-bounces@aps.anl.gov] On Behalf
> Of Eric Norum
> Sent: Thursday, March 15, 2018 11:27 AM
> To: Amien Crombie <acrombie@tlabs.ac.za>
> Cc: EPICS Tech-Talk <tech-talk@aps.anl.gov>
> Subject: Re: Asyn - max addresses per port
> 
> There is nothing in ASYN that would prohibit this.  I have drivers with dozens of addresses
> on a single ASYN port.
> 
> 
> > On Mar 15, 2018, at 9:19 AM, Amien Crombie <acrombie@tlabs.ac.za> wrote:
> >
> > Hi
> >
> > I have a 8-channel Asyn driver that allows me to have 1 port with 8 addresses. Each
> address holds a int32.
> >
> > Now I want to go to 48 addresses...is it possible?
> >
> > I'm using asyn-4-21
> >
> > Amien
> >
> 
> --
> Eric Norum
> eric@norum.ca
> 
> 
>