Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Wed, 9 Sep 2009 09:56:17 -0500

On Wednesday 09 September 2009 07:34:52 GOURNAY Jean-Francois wrote:
>
> I did more systematic tests and I have this strange situation:
>
> ASGVAL  UAG      spiral2  spiral2mgr      gournay
>
> 1       tous      W        W               W        OK
> 2       develop   -        - (should be W) -        WRONG
> 4       physique  W        -               -        OK
> 8       gournay   -        W (should be -) W        WRONG
>
> W : database WRITE access
> - :  no write access
>
> I modified the CALC expressions accordingly to Martin suggestion :
> CALC("A&1") instead of CALC("A&1=1").  But I don't think I have to write
> CALC (A>0&&A<2) as my A value comes from a longout record.

You're right there, but for historical reasons the relative precedence of 
the ">>" and "=" operators are different in C and CALC, so you do need to 
change your expressions:

>             CALC("A&1=1")
As Marty suggested "A&1" is sufficient here

>             CALC("A>>1=1")
CALC actually evaluates this as "A>>(1=1)" which is not what you mean.  You 
could use "(A>>1)=1" but I would suggest "A&2" here instead.

>             CALC("A>>2=1")
"A&4"

>             CALC("A>>3=1")
"A&8"

Using fewer operators will also parse and execute faster.

> This message sent yesterday didn't show up.

That's because you actually sent it to tech-talk-bounces@aps., not to 
tech-talk@aps., and I didn't get a chance to forward it manually before you 
re-sent it.

HTH,

- Andrew
-- 
The best FOSS code is written to be read by other humans -- Harold Welte

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System