Fritz,
One possibility: add special BI device support and
associated device addressing for a pseudo binary IO
in your device which returns the status from the last
IO request. You might have specialized information in
the parm field of INST_IO or some other addressing format which
binds with your device's status. For example, if the addressing
is typically "CARD 0 SIGNAL 4" then the addressing for
the associated device status might be "CARD 0 SIGNAL 4 <STATUS>".
The downside of course is that you would need an additional
BI record for each signal, and I understand that you have more
than a few signals there.
We could avoid this overhead by adding a new pseudo field name to
all records which does not exist in the recod but is instead fetched
through a new entry at the end of the record support entry table.
This RSET entry might then call a new entry at the end of the device
support entry table.
Another way to solve this problem (long term) would be to allow
certain records to be created on-the-fly from a template only
when clients are looking at them. These pseudo BI's communicating
with your device's status would therefore only exist if a client
was attached to them.
Alternatively, we could look at device support extensibility
mechanisms for the "STAT" field.
Jeff
> -----Original Message-----
> From: J. Frederick Bartlett ([email protected])
> [mailto:[email protected]]
> Sent: Thursday, May 25, 2000 11:21 AM
> To: [email protected]
> Cc: [email protected]
> Subject: Status return from EPICS device support
>
>
> I have a question for the experts. Is there a standard field in all
> records in which detailed device status (status from device support)
> may be placed where is is accessible by a database get operation.
>
> My particular difficulty appears with asynchronous device support
> for the MIL/STD1553B bus. We have a controller for the 1553 bus which
> generates an interrupt at the end of a bus transaction. The 1553 bus
> driver reschedules record "processing" (PACT is non-zero at this point) at
> interrupt time via a call to callbackRequestProcessCallback, passing a
> longword with bus I/O completion status. I need to save this status in
> a standard record field (one that all records have) so that, if there
> was an error, the application program may retrieve it. Any
> suggestions?
>
> Fritz Bartlett
>
- Replies:
- Re: Status return from EPICS device support Andrew Johnson
- References:
- Status return from EPICS device support J. Frederick Bartlett ([email protected])
- Navigate by Date:
- Prev:
Re: archiver record Albert
- Next:
Re: Status return from EPICS device support Andrew Johnson
- Index:
1994
1995
1996
1997
1998
1999
<2000>
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
- Navigate by Thread:
- Prev:
Status return from EPICS device support J. Frederick Bartlett ([email protected])
- Next:
Re: Status return from EPICS device support Andrew Johnson
- Index:
1994
1995
1996
1997
1998
1999
<2000>
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
|