Changing HMI password with the PLC

alanze

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Jan 2019
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I have been asked to find out if there is a way to change the different user passwords for the HMI through the PLC. We use FactoryTalk View Studio for the HMI and rslogix5000 for the PLC. Currently we have to change the password in the HMI and then upload that program every time which is annoying. Is there a way to just change something in the PLC and have the password update automatically? I am pretty new to both PLC and HMI programming. Any help is appreciated.
 
;)
I have been asked to find out if there is a way to change the different user passwords for the HMI through the PLC. We use FactoryTalk View Studio for the HMI and rslogix5000 for the PLC. Currently we have to change the password in the HMI and then upload that program every time which is annoying. Is there a way to just change something in the PLC and have the password update automatically? I am pretty new to both PLC and HMI programming. Any help is appreciated.

Hi Alanze.

Firstly, welcome to the forum.

Yes this can be done, however I must state that there will not be any encryption or security regarding usernames or password, this data could be freely retrieved from the controllers memory.

So your looking at 2 bits of information per User, the username (STRING) and the password (you can restrict this to a signed/unsigned number if you wish or again use a STRING), maybe also an access level?. You could create this as a structure, then combine in an array.

ARRAY[0..15] of 'your structure name', this will give you 16 slots for users, obviously if you want more; you can just expand the array.

Then you just need some logic to verify the password they have entered matches what is stored in the PLC, if all is good then set whatever access level is given in their credentials. Further steps could be to monitor activity timeout, aswell as login/ logout and change password buttons.

Does this make sense to you?

If you need further informatio; just let me know.


Regards

Daniel
 
Yes that makes sense. We do have something similar in a way. When a part is scanned with a bar code scanner the PLC checks what is scanned against what is in the BLADE system. I could probably use similar logic, but I am unsure of how to pull the password typed in the HMI to the PLC.
 
You will need a another Integer stored in the PLC, the operator selects a username (at this point the PLC knows what password to check). The password they enter gets stored in that integer then the PLC just needs to compare them; if they are the same- then set the approriate access level. If not you just need to create a boolean to say the password is wrong.

After an attempt has been made to login; I would clear down the password field to '0' ready for a retry or for a new user to login.

Once logged in. Maybe you can write some logic to allow someone to change their password (otherwise it will always need to be done in the controller tags)

Regards

Daniel.
 
I have been asked to find out if there is a way to change the different user passwords for the HMI through the PLC. We use FactoryTalk View Studio for the HMI and rslogix5000 for the PLC. Currently we have to change the password in the HMI and then upload that program every time which is annoying. Is there a way to just change something in the PLC and have the password update automatically? I am pretty new to both PLC and HMI programming. Any help is appreciated.

Not a Rockwell guru, but doesn't FactoryTalk allow you to have a user management screen where you can change the passwords?
 
Not a Rockwell guru, but doesn't FactoryTalk allow you to have a user management screen where you can change the passwords?

Yes it does, unfortunatley it works on a Windows-based system where such users are created from the windows runtime and adding usernames/ passwords has to be done in FTView.

There is a user management screen that can be accessed, but only on the later firmwares (iirc).

A lot of people tend to avoid this system and go down the path of doing it inside the PLC.

Regards

Daniel.
 
Yes it does, unfortunatley it works on a Windows-based system where such users are created from the windows runtime and adding usernames/ passwords has to be done in FTView.

There is a user management screen that can be accessed, but only on the later firmwares (iirc).

A lot of people tend to avoid this system and go down the path of doing it inside the PLC.

Thanks for the clarification.
 
Here is an example of what I would do for something like this.

Taking advantage of array pointers means that this code can be simplified to only a few rungs, the code is written with the assumption that you require no more than 20 users; and all the usernames and passwords contain numerical values only. Need more users?...simply expand the array.

Seems to work as expected on my test bench with RSView over OPC but may need some "fine" tuning but gives you an idea of how you could approach this.

(this is written in V16 btw)...

Regards

Daniel
 
What I have done in the past is attach RFID readers that can read the frequency of employee badges and hooked it to the USB port to act as a keyboard. I then have a numeric input (since the badges were not alphanumeric) labeled "logon." In the PLC I would have a lookup table that searched for a matching badge number and latched a bit if there was a match, then clear that input. The bit latched was corresponding of the user access level and I just used the visibility animation tied to the bits to toggle access screens. Worked great for me.
 
Here is an example of what I would do for something like this.

Taking advantage of array pointers means that this code can be simplified to only a few rungs, the code is written with the assumption that you require no more than 20 users; and all the usernames and passwords contain numerical values only. Need more users?...simply expand the array.

Seems to work as expected on my test bench with RSView over OPC but may need some "fine" tuning but gives you an idea of how you could approach this.

(this is written in V16 btw)...

Regards

Daniel

So I tried opening your file but because it's an older version we cannot open it. We can only go back to V20. Is there anyway for me to convert it to a version that we can open it with? Or even taking a screen shot of what you have would be better than nothing.
 
So I tried opening your file but because it's an older version we cannot open it. We can only go back to V20. Is there anyway for me to convert it to a version that we can open it with? Or even taking a screen shot of what you have would be better than nothing.

Ill get it to version 20 for you tonight.


Regards

Daniel
 
See attached file in Version 29.

This will get you started; however there are a couple of additional features I would look at adding.

1. Inactivity Timeout- Log the User out if there is no active user on the Interface, if you are using Panelview you should be able to connect this to a tag.
2. Create User- Currently this has to be done in the Controller Tags, however this could be added to the Functionality of the software if needs be. You will need to consider the size of the Array for this (ie if the Array is full, then dont accept any new users).

https://anonfile.com/baJ5P0sebc/User_Management_V29_zip


Regards

Daniel
 
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