ScadaMobile uses MW3998 as default validation tag for S7 controllers. This is fine for S7-1200 but it fails into an out of range address on some controllers such as the S7-300. Therefore, you need to set a custom memory area for the validation tag to work on your PLC. To do so you must enter the following attribute in any row on your csv file. For example if you want to use MW200,
validation_tag = “mw200″;
Please use lowercase letters as shown above. You can use any MW address. This attribute tells ScadaMobile to look at MW200 for a validation code. You must set a non zero value in MW200 in your PLC, and enter the same exact hexadecimal value in the connections tab in ScadaMobile. Upon connection, SM will read the value from your PLC and will only continue with communications if both values are the same.
I can tell that this is a common source of trouble because the default validation tag can not be used on some S7 controllers, so it forces users to set a custom one. To prevent this problem in the future we are changing the default validation tag to MW998. That way virtually all S7 controllers will communicate first time without having to set anything.
I hope that helps. Let me know in case you need some additional info.
