Re: [foxboro] Active Foxview Display
- From: "Easley, Jack" <Jack.Easley@xxxxxxxxxxxx>
- To: "foxboro@xxxxxxxxxxxxx" <foxboro@xxxxxxxxxxxxx>
- Date: Tue, 20 Dec 2011 08:32:57 -0600
You are correct that pref -DMNAME ST0 to display this display manager variable
value is safe.
It is the pref -DMNAME dmcmd "dmcmds" that can be extremely dangerous,
especially while learning display manager commands, or even have a fat finger
later.
The main danger with using pref is just how flexible and powerful display
manager commands are. They can control process just as easily as they can
control displays. You can execute a display manger command from any Foxboro
computer to any display on any other Foxboro display. The main danger is that
while the display executing the command is easily traceable...to my knowledge
(although I am not a cyber forensics expert)there is no way to track where the
display manager command was issued from originally (who done it). Very bad in
today's cyber paranoid world. And there is also the fact that there are usually
a lot more DMNAMES than WPs/AWs making it very easy to use the wrong dmname and
cause an inappropriate action on another WP/AW. However, pref's ability to
control process is the very scariest part.
Pref is great and powerful stuff, just maybe too flexible and powerful for
today's control environment!
Jack Easley
Sr. I&C Technician
Luminant Power, Martin Lake Plant
Phone 903.836.6290
jack.easley@xxxxxxxxxxxx
-----Original Message-----
From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx] On
Behalf Of Ricardo Abech
Sent: Tuesday, December 20, 2011 6:32 AM
To: foxboro@xxxxxxxxxxxxx
Subject: Re: [foxboro] Active Foxview Display
Thanks Terry …. I was under the impression that the "pref ST0" or "pref ST1"
only collected the actual display and did not execute anything. So you mean
that calling the pref is actually recalling the display or affecting it some
how?
Thanks!
On Dec 20, 2011, at 10:26 AM, Terry Doucet wrote:
Ricardo,Careful with pref because it can force a FV or DM command to execute.
If you use the variable that Bud suggested with an omget or omgetimp you can
get the WP to return the name of the existing (or last) display without
re-calling the display or executing any other commands.
Pref can be dangerous if you execute it while an Operator is using the station
where you force the pref to execute.
Terry
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