[foxboro] Remote Draw Applications

When the I/A Series was developed, there were a number of constraints on the
developers. One of them was the lack of technology for drawing on a WP from
an AP. Remember that WP's were diskless then - basically thin clients.


Consideration of X-Windows was made, but the implementation was too large
for the OS and hardware we chose (8086 and Venix with a 64K data model). So,
we implemented a similar, but different technology that is known as "remote
draw".


This technology is implemented through some background processes and the I/A
Series HMI library.


This technology and the HMI library use in turn a version of the Remote File
System (RFS). RFS was AT&Ts competitor to Sun's Network File System (NFS).
Again, we faced constraints due to the 64K memory model of Venix. Again, the
decision was made to implement our own version - micro-RFS.


If you run ps -ef | grep urfs on a Solaris system you will see:


    root  1217  1117  0   Feb 15 ?        0:00 /usr/fox/exten/urfs_xserver
-m /etc/fox/dsamap
    root  1219  1117  0   Feb 15 ?        0:00 /usr/fox/exten/urfs_om_daemon


The former of these applications is used to support our remote draw
applications.


The remote draw applications are the ones that display on the WP, but run on
the AW/AP. They include, but are not limited to:


* The ICC
* The I/A Series Historian configuration tools
* The DM's Display Builder and Display Configurator


Our remote draw technology works differently from X-Windows, but it can be
"routed" through an X-Client (like the AW51) to an X-Server (like a WP or PC
running Hummingbird's eXceed). However, there are limitations. For example,
for eXceed to work properly with these applications you must enable the
"backing store" and other options. Because our remote draw facility needs
such support in its clients.


GoGlobal does not have these options and for that reason, it does not handle
updating the display of "remote draw applications" properly.


As a side note, with the introduction of NT back in the mid-nineties (V5.x
was NT only), we made the decision to not port micro-RFS to the Windows
product line. This decision resulted in the loss of remote draw support,
i.e., a WP70 cannot raise the ICC from an AW70.

What we did instead was make the X-windowing applications by changing the
implementation of the HMI library. With this change came the use of  eXceed
to display all of our I/A Series HMI programs.


These programs included (in beta V5.x at least), the DM and its
configurators, the ICC, the IAS Historian, and SMDH (the System Monitor's
Display Handler). That's why eXceed is on all AW70s


The reason that I mention it is that some customers have realized that and
actually call up the ICC from WP-70s using the X-Windows facilities. So, you
may hear people say that they can configure from any WP-70 while others say
they cannot. 


And now you know the rest of the story


(apologies to Paul Harvey for the theft of his closing line)



Regards,

Alex Johnson
Invensys Systems, Inc.
10707 Haddington
Houston, TX 77043
713.722.2859 (office)
713.722.2700 (switchboard)
713.932.0222 (fax)
ajohnson@xxxxxxxxxxx
For the latest information on ArchestrA, go to
www.invensys.com/divisions/Archestra.html

 -----Original Message-----
From:   stan [mailto:stanb@xxxxxxxx] 
Sent:   Tuesday, February 18, 2003 12:19 PM
To:     foxboro@xxxxxxxxxxxxx
Subject:        Re: [foxboro] Sanity check on Go Global


On Tue, Feb 18, 2003 at 09:08:28AM -0800, Ted Jirik wrote:
> 
> Tim,
> 
> Yes the ICC works exactly as it does on the local head. There are no
resize 
> issues because VNC is running a second copy of the Open Look window
manager 
> so the ICC removes the resize handles from the ICC window as well as any 
> other remote draw application's window. I don't have any problems with 
> missing buttons on a close/restore and save unders and backing store work 
> as expected.

Sorry too keep asking the same question, bit I have not gotten an answer
yet (at least not one I understand), and I think understanding this is key
to where I'm trying to go.

What exactly do you mean by a "remote draw" application?

-- 
"They that would give up essential liberty for temporary safety deserve
neither liberty nor safety."
                                                -- Benjamin Franklin
 
 
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