AnsweredAssumed Answered

Formula vs. Function Name

Question asked by VRFuser on Aug 12, 1997
Hi Juan Carlos!

You are quite right, and I am well aware of it, but its the only kind
of  "multitasking/ timeslicing" HP-vee can do in the 4.01 version.
Let's hope for some later improvements.
It's better than no timeslicing at all. I use interface event on the
RS232 to avoid to get timeout lockout for my other tasks. It works
OK for my application.

Bjorn Kristian Kleven








> Date:          Tue, 12 Aug 1997 15:33:44 +0200
> To:            hpvxd_xc%hpislsup.lvld.hp.com@hplb.hpl.hp.com
> From:          Juan Carlos Martin <jcmar@mdr.indra-espacio.es>
> Subject:       Re: Vrf:Formula vs. Function Name

> At 08:03 12/08/97 +0000, you wrote:
> >Hi Mike!
> >I have used call objects with function name input to create a
> >programable multitasking system in HP-vee, and it works well. I also
> >tried with the formula objects first, but they didn't work.
> >However I hope HP can make the formula objects with formula input
> >work with timeslicing in the future, because they are more useable
> >than a call function object.
> >
> >Bjorn Kristian Kleven
> >Ericsson AS, Norway
> >
> >
>
> Bjorn,
>
> You are not using multitasking but multithreading. That is: your programs
> can execute several objects and functions with several objects at the same
> time, that is several threads at the same time. However, your programs
> cannot execute several VEE objects (like for example, if/then/else or
> formula or Direct I/O objects) at the same time. That is, you execute one
> step one each of these objects. Only some objects like delay are executed at
> the same time than the rest.
>
> >From my point of view, this is specially important for equipment
> communication objects. If you use a Direct I/O object, for example, you put
> a timeout of 2 minutes (and your equipment is not present), your program
> will be stopped 2 minutes in that object until timeout is expired. In a
> multitasking environment this is avoided: you are executing other objects at
> the same time you are communicating with the equipment.
>
> >
> >>Is there a difference between the formula control input of a formula
> >>object
> >> and Function Name control input of a Call object?
> >>
> >> I am trying get time slicing working and it will not work if a formula
> >> control input of a formula object is used as stated on page A-6 of the
> >> Advanced Programming book, but maybe a call object with a function name
> >> input will work. Any thoughts?
> >>
> >> Mike Gustin
> >> mgustin@smsmfg.sme.siemens.com
> >>
> >>
> >______________________________
> >Bjoern Kristian Kleven
> >Ericsson AS
> >Norway
> >______________________________
> >Mail:  etobkle@eto.ericsson.se
> >Memo:  ETO.ETOBKLE
> >Fax:   +47 66 98 10 95
> >Phone: +47 66 84 16 03
> >______________________________
> >
> >
>
> Mike,
>
> I have tested you information and you are right.
>
> However, I think it is not bad. I think that in some cases you specially
> want to execute a function and do not execute any other object until that
> function is finished. It is good to know that kind of behavior of
> Formula/Call objects. It would rather if formula objects could have a
> selection box (into properties) in order to choose the way the called
> function is executed: time slicing or not.
>
> Regards,
> ______________________________________________________
>
> Juan Carlos Martin
> E-mail     : jcmar@mdr.indra-espacio.es
> Phone      : 34-1-3963995
> Fax     : 34-1-3963912
> Earth Stations Department
> INDRA ESPACIO / MADRID /SPAIN
>
>
>
______________________________
Bjoern Kristian Kleven
Ericsson AS
Norway
______________________________
Mail:  etobkle@eto.ericsson.se
Memo:  ETO.ETOBKLE
Fax:   +47 66 98 10 95
Phone: +47 66 84 16 03
______________________________




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