Re: streamDevice 32-bit hex value read problem

[Dirk Zimoch <dirk.zimoch@psi.ch>]

Hi Marty,

%R is the floating point raw format. The integer raw format is %r.

(Here I assume that you really get binary data, not the hex string 
"ffffffff ffffffff", which would be a case for %x.)

I am a bit confused, because ffffffff ffffffff is 2 32 bit values or 1 
64 bit value.

Stream device can read a 32 bit big endian signed integer with %4r, a 32 
bit big endian unsigned integer with %04r, a 32 bit little endian signed 
integer with %#4r and so on.

On 64 bit machines, StreamDevice can even read 64 bit integers with %8r, 
but no EPICS record can store them. So you are limited to 32 bit signed 
or unsigned at the moment.

In case you do not have binary data but hex strings, (and the space in 
your format suggests that) you should use %x.

Dirk


On 12.11.2012 21:21, Martin L. Smith wrote:
> I'm trying to read a 32-bit hex value like ffffffff ffffffff using
> EPICS R3.14.12.2, streamDevice 2-5, and asyn 4-19 on 64-bit Linux OS.
>
> When I read these values using the following protocol:
> get_ilock {
> out "din";
> in "%(\$1FirstInterlockWord.VAL)8R ",
> "%(\$1SecondInterlockWord.VAL)0R";
>
> ExtraInput = Ignore;
> }
>
> Both records are longin records and no matter if I use the 8R or 0R I
> always get the same result:
>
> ID06ds:FirstInterlockWord 11/12/12 14:03:02.743812335 -2147483648
> ID06ds:SecondInterlockWord 11/12/12 14:03:02.743823268 -2147483648
>
> Turns out that this is hex value 80000000
>
> If I use a strngin record I can see that I'm getting the expected data.
>
> Is this the largest value that I can read using streamDevice or is there
> some other way that I should try to read these values?
>
> Thanks,
> Marty