Re: Multiple device support for a record type

[Stefen Paul <stefen4114@gmail.com>]

Hi,

Ya Michael ... you are right that one shouldn't feel bound to use VME_IO just because it has VME in its name. Even initially I had issues using this but now I've managed to make it work for A24 by using relative addressing and some other custom tricks.

Thanks Ralph ... for the useful tip of having the constraint that the combination of tag and record type must be unique. I'll use this method and will update you on the same.

I've one one more question in the same line :

Presently the method I use to build device support remains application specific. I add the device support C files in the 'src' folder of the app and then make necessary entries in the makefile and .dbd file. This way I get the device support for the records in that application.

Is there a way to include device support globally (at the EPICS base level) so that I do not need to included it everytime at the individual application level and the support is automatically available to all the subsequently created applications made using makeBaseApp.

Thanks,

Stefen  

On Thu, Aug 11, 2016 at 5:08 PM, Ralph Lange <ralph.lange@gmx.de> wrote:

Hi Stefen,

On 11/08/2016 12:39, Stefen Paul wrote:

I've built device support for ai record for a vme based ADC board.
I've used the following to add the support:
    device(ai,VME_IO, devAiADCtype1, "HW Channel");

Now I want to build device support for ai record to support one more type of vme based ADC board to be used in the same system.
How do I do it ? Should I write something like :
    device(ai,VME_IO, devAiADCtype2, "HW Channel 2");

Yes, that's the way.

The constraint is that the combination of tag ("HW Channel") and record type must be unique.
I.e. you can and should support multiple record types for the same hardware using a single tag.

Please use something descriptive as the tag, e.g. for a VME-6854 card by MyCorporation something like "MyCorp VME-6854".

If you have multiple functionalities in one support (for one hardware) that map to the same record type, e.g. different configuration options and digital outputs that all use a bo record, the distinction is usually done by a tag in the free text part of the INP/OUT link.
If you need to code more configuration inside a single record instance than the free text allows, you can add info() structures to the record. (Be aware, though, that info structures are not visible remotely through Channel Access.)

Cheers,
~Ralph