MMS APPICATION FOR DATA READ/WRITE
> "Is it required to configure the access variable in the controller which is sending the data"
Yes, you must declare an access variable in the Controller Access variables. Note that this is at the hardware level.
But honestly, you should consider using "Communication Variables". They are much easier to understand and troubleshoot.
> "message came that while downloading may be CPU will restart."
Whenever you change a program in any way you have to warm start. This is normal.
> "is it OK to download or whether the CPU will be effected."
Probably. Did the message say you have to "cold start" ? I this case something else is going on. Otherwise, yes its OK to download. If you have never done a download before there are some things you should know ...
- MMS communications will stop for a few seconds. This is normal. Write your code so that it can handle this correctly
- Variables that are not "retained" will reset to their default value. Make sure your code can handle this ( ie set the "retain" attribute properly)