I could assume an Ethernet connection here, but I won't.
An "S7-1200" is a piece of hardware. "FactoryTalk Machine Edition" is a piece of software. The S7-1200 is limited in what it can "speak". If using the Ethernet port on the S7-1200, then PROFINET is the protocol of choice.
FactoryTalk View ME can be used to develop runtime applications for many different HMI terminals. Depending on which, it can be used to "speak" many different protocol languages.
So which HMI terminal are you looking to "speak" to and which port do you want to use, Ethernet? (Damn, I'm assuming now).
The S7-1200 does not support the EtherNet/IP protocol natively, whereas the Allen Bradley Ethernet based PanelView terminals do. You would have to interface between the two, if using Ethernet.
One such popular interface is the PLX31-EIP-PND. This is an EtherNet/IP to PROFINET IO Device Gateway from Prosoft Technology...
You could use the Kepware OPC software that comes with ME.
I don't think the Kepware server would support the optimized data blocks in the 1200. If correct you could only communicate to I/Q/M and non optimized DB's.
I doubt the S7 200 driver will work; it is a completely different platform from the 1200. However, an S7 300 driver might work if you create the 1200 data blocks in "standard mode" instead of the default mode of "optimized".