Micrlogix 1200 PID and a RedLion HMI

Setup:
1762L24BXBR SER C REV B FRN 12
RedLion G306A000
I'm talking to the RedLion DF1 Full Duplex through the Prog/HMI Port on the ML1200.

My customer wants to be able to tune the PID from the HMI.
Since the RedLion cant directly access the PD file created by the ML1200 I have a MOVE instruction like N7:15 > PD9:0.KC
(N7:15 being the integer the HMI writes to). This works fine but if you go online with the PLC and tune the PID the MOVE instruction overwrites any changes made. I would like for the changes made to PD9:0.KC while online through the PID "setup screen" to update N7:15.
It seems like this should be easy but I cant seem to figure it out. Any help would be greatly appreciated.
Thanks

You can put a toggle bit in that when you are online with the PLC you toggle this bit and the HMI will not over write the data. Then you are not online the HMi be the master and will copy to the PD file.

Thanks good idea. I think I will do just that