You can use a write, the way to use is:
ResDBClientPN = "94939291"
'Writes the value to PLC string and then to STATUS integer register
Try
EthernetIPforCLXCom1.Write("ResTestData", ResDBClientPN)
EthernetIPforCLXCom1.Write("ResTestStatus", 15)
Catch ex As System.Exception
System.Windows.Forms.MessageBox.Show(ex.Message)
End Try
I wrote two different values, the fisrt one is a string ("ResTestData") followed by the value you want to write (ResDBClienPN), I used a variable as an example, but you can write text directly, depending on what you want to do. The second value is an integer label ("ResTestStatus") into who I wrote a value of 15.
Remember to do all this inside a Try...Catch, as it will prevent your application from frozing with an error when the PLC is offline, if you want you can write a message like "Cannot write values to PLC, must be offline" or alike to warn the user, into the message box, but this is totally up to you.
Remember you are not "forcing" values, think of this program as exactly how it works an HMI in real life, so you are reading and writing values like any other device into the PLC.
The same applies to .Read method, but you only specify the tag or direct address like N7:0 that you want to read.
There is a topic related to this method to be an asynchronous way to write and read, and can lock the user interface from a moment to several time, not being the best method. To read a value from the PLC use basic labels, or better a datasubscriber (it does not generate a visible control if you do not want the user to see something) and will be much more efficient in communication use as is designed with that in mind, basic labels have datasubscribers embedded. I am not aware if Archie added a different method to write values, but so far this has worked fine for me.
A lot of good information is spreaded in here in the forums and you need to read a lot to get it, but it is worth it.