RTU card of SCADA systems
You do not offer very much information, however this is the basics. An RTU receives and transmits information to and from a master control station. Typically that being a central control station, such as a control office in a power utility. The satellite remotes can be electrical substations, for instance, which will have their switching remotely controlled. These satellite stations will report the position of switching and can also report real time data such as voltage or current readings. The "card type" RTU is commonly being replaced by PLC's which usually use Ladder logic so as the functions can easily be reprogrammed.

EDIT:
You should be able to get some clues as to the cards function by looking up the chip numbers. The older systems did not have analog capabilities, not sure about this one.

How many pins are on the header? Could possibly be an  SBC with format  PC-104 compatibility?