Password protecting a screen

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Thread Starter

Daniel Boudreault

Hello List,

I was wondering if someone out there has implemented
a method to password protect a screen for an A-B Panelview 550.

I need to password protect a numeric input.

I was thinking of having a separate numeric input for the password
entry. First the operator would enter the number in the regular
numeric input, then he will next enter the "password" numeric entry
input... The PLC will be doing the verification of valid password... if
the password is valid then the new number will be used...

Thanks in advance, Dan Boudreault
 
M

Martin Cutajar

Daniel,

Another possibility is to have the numeric input coded, this could be done
by:

i) simply adding password digits to the input, (at the beginning, end or in
the number) which would then be truncated off in the PLC program.

ii) using some other algorithm to generate permissible inputs from actual
numeric values to be inputed, which could them be verified in the PLC by
reversing the algorithm.


However the above depend on the level of security required and the
collaboration of the operators.


Regards

Martin.
 
P

Phil Costantinou

Mr. Daniel Boudreault, and the rest of the Automation List-
I've used the method suggested below (by Antonio_Fern E1ndez_Cant) using the panelview configuration and status words
for the displayed screen number; it works well enough.
In a nutshell, you create a "gatekeeper" screen (or a dialog box on an existing screen) where the password is entered
to prevent un-authorized access to the secure screen, and program additional rungs in the PLC program to read the
password and to cause the panelview to display the secure screen.
A good idea would be to also protect the secure features from modification unless the correct password has been
entered. Additionally, create and program a timer to disable password protected features if no panelview activity
occurs after a period of time, and to return the panelview to the default, lower security screen.
If I remember correctly, the panelview documentation includes some examples. If you need help, call me or write me
(see below).
-Phil

> From: "=?iso-8859-1?Q?Antonio_Fern=E1ndez_Cant=F3n?=" <[email protected]>
>
> There are some configuration words to the PanelView where you can write the
> time, date, the number of screen , etc. You can also read the actual number
> of screen that PV is displaying. If this number of screen is protected (Ej.
> The display where the operator input values) and the password is wrong you
> write the number of one screen whrere you display this message: "Screen
> Protected. Input the correct password".

********************************************
Phillip G. Costantinou, P.E.
Instrumentation and Controls Engineer
I.C. Thomasson Associates
2950 Kraft Drive
Suite 500
P.O. Box 40527
Nashville, TN 37204-0527
(615) 346-3400 Switchboard
(615) 346-3499 Direct to desk
(615) 346-3550 FAX
[email protected]
http://www.icthomasson.com
 
A

Antonio_Fernández_Cantón

Hi, List,
There are some configuration words to the PanelView where you can write the time, date, the number of screen , etc. You can also read the actual number of screen that PV is displaying. If this number of screen is protected (Ej. The display where the operator input values) and the password is wrong you write the number of one screen whrere you display this message: “Screen Protected. Input the correct password”.
 
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Using the screen controll bits in the BTR/W you can prevent the PLC from allowing screen changes if the password is not equal to an expected value.
 
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Trevor Ousey

Daniel,
One way which I’ve done this is to have a password screen which has individual buttons direct to the PLC. Then write a routine that when a button is pushed that multiplies the register by 10 (or 16 depending whether its dec or bcd) and moves the button value to the LSD of the register. You may only want to display # for each digit entered.
Trevor Ousey
 
D

darcy oldfield

Although the screen password idea is good, because you can set it up so you can change the password on the fly. I like to use a physical key connected to a input. When you use the key you then display and enable a screen switch button which is hiden when it is not active.

If you would like just software based you can try this. Take an input word from the Panelview which is your (set password) take another input word from the Panelview which is your (entered password). In the PLC logic compare the two numbers with the Equal command and set a bit when they are equal. Use this bit to enable and show a switch screen button. If you want the PLC to change the screen for you then you may have to use a one shot so that it doen't try to keep you on the same screen or you could set the value in the (enter password) back to 0 after changing screens.

if you need more help just let me know

Your Truly

Darcy Oldfield
 
Screen security was implemented in release 3.50 of PanelBuilder sw. and firmware rel. 4.0. You no longer have to use ladder logic to protect screens.

Jarvis
 
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