send int from HMI to plc

I have a question. In my HMI i have a dropdown menu, with integers as value. I want to send te selected value from the dropdown list to the PLC, but i cant figure out how to do it.
I have in the PLC a MD entry, where i would like to put the value.

Can someone provide me the steps or the direction how to do it.

Regards

What PLC? What HMI? We need some clues ...

Hey Welcome to the forum!!!! if you can, please provide the type of HMI you are using and the type of PLC as well, this is because different manufacturers have different methods of accomplishing things.

Sorry for that,

The HMI is a siemens tp 177B 6"color and the PLC is a siemens 300, CPU 315-2 pn/dp. I'm using wincc 2008 sp2

I haven't dealt with the specified brand of HMI or PLC that you stated, but, usually an INT register is read from the PLC, say for example, if you are referring to the drop down as maybe a multistate indicator, you can reference the Integer register from the PLC and assign different states based on the "value" of the INT register in the PLC. If you are trying to do it the other way where the HMI is now sending an INT value to the PLC then that's something i would like to know myself, Hope this helps

When you create the drop down you should have an area where you specify a "tag" int the PLC.

This will be a symbolic name that in the tag table you point to a memory area in the PLC. (e.g. MW20, DB4.DBW10) assuming you defined the memory area as an INT in the PLC also.

The drop-down menu is called a "Symbolic IO list" in WinCC Flexible.
This is an alternative to a regular "IO Field".
The difference between an IO Field and a Symbolic IO List is:
An IO Field allows the user to enter any value that the data type allows.
A Symbolic IO List only allows the user to select one possibility from a predefined list of entries.

If you want to setup a Symbolic IO List, in the "Process" property field you link it to a PLC tag.
In the "Display" property field you link it to a Text list.
If there is no Text list yet, you must create it.
First time it is best to create the text list under "Texts and Graphics lists" in the project tree.
When editing the text list, in the column "Value" you enter numbers that the tag must have in the PLC. In the column "Entry" you enter what text is to be displayed in the drop-down list.
After creating the text list, you can link it to the Symbolic IO Field.