Logon systemfunction parameters

Hi!

For a project (WinCC Advanced V15) I need to log in some users at the start of HMI runtime. I’m trying to do this with a script which I run at the startup screen. When the startup screen is loaded, I set a boolean tag. In the script I check if the boolean is true or not. If it’s true, then I want to log the users in. Therefore I want to use the “Logon” function.

This function logs on a user on the HMI device and has two parameters, Password and Username. Password, is the tag from which the password for the user logging on is read. User Name, is the tag from which the username for the user logging on is read. I would like to know how to use these parameters. How can I link a password or username to a tag? I don’t see the option to do this, either for an HMI or PLC tag.

This is the manual where i get the info about the "Logon" function.
https://support.industry.siemens.com/cs/ww/en/view/109755216 

Thanks!

Hi ale.rdv

My reasons are different, but I also do, under certain circumstances, force a particular login at the HMI. But there are three difficulties with it that you will need to understand. In any case, first the technique I use:

I detect the circumstances for forced login in the PLC and use it to toggle a flag. It doesn’t matter whether the flag goes high or low because the detection at the HMI is only value change. So, on detection of the flag change of value in the HMI tags, I call the Logon function reading PLC registers for the username and password.

So, Difficulty no.1 For the value change function to be called, there has to be a control referencing the tag on the active page. If you want the forced login to work regardless of which page is currently active, you will need a control referencing that tag on every page. For me, I have a header, defined in the template that is used on every page, so I can just put a hidden dummy control referencing the tag on the template to make sure that it is always there.

Difficulty no.2 The registers in the PLC that hold the username and password values must match those that are currently set in user administration. If someone with user administration login authority who doesn’t understand that this feature has been setup or how it works, sees fit to change either username of password, then the forced login will not work. At least, until the PLC registers are corrected to the new login details.

Difficulty no.3  Siemens, in its faceless behemoth’s infinite wisdom, has seen fit to put in a function that you cannot disable whereby every time you call the Logon function, the PLC registers containing the login details are automatically cleared. So, you need to have further buffering registers holding the login details, and every time the Logon function is called, you need to also trigger a copy of the buffering registers into the ones actually used by the logon function.

ale.rdv

Hi!

For a project (WinCC Advanced V15) I need to log in some users at the start of HMI runtime. I’m trying to do this with a script which I run at the startup screen. When the startup screen is loaded, I set a boolean tag. In the script I check if the boolean is true or not. If it’s true, then I want to log the users in. Therefore I want to use the “Logon” function.

This function logs on a user on the HMI device and has two parameters, Password and Username. Password, is the tag from which the password for the user logging on is read. User Name, is the tag from which the username for the user logging on is read. I would like to know how to use these parameters. How can I link a password or username to a tag? I don’t see the option to do this, either for an HMI or PLC tag.

This is the manual where i get the info about the "Logon" function.
https://support.industry.siemens.com/cs/ww/en/view/109755216 

Thanks!

 You don't need the boolean tag to call the script. You just have to call your script in the events of the start screen under 'Loaded'.

You can write a username and password to a tag in a script and logon with them:

OR you can do it with tags:

Therefore, you first have to create 2 internal tags of type WString (Tag_Password and Tag_User in the example).

To put the actual username and password in the tags, you can use the function SetTag and select 'String' in the value input. You can use it with the event 'Click' of a button for example.

But I don't know when or how you want to change the user that has to be logged in at the start of course.

!!!The actual password and user must already be configured in the user administration of the panel!!!