Provided is a remote terminal device having an industrial versa module eurocard bus (VMEbus) structure and including a main module that receives control logic information of a field device from an input/output module, and a programmable logic controller (PLC) function module that receives the control logic information from the main module, performs a logic corresponding to the control logic information, and outputs a result of the performed logic. The PLC function module includes a dual port RAM including a plurality of memory areas, and a PLC chip that reads the control logic information written on one of the plurality of memory areas, performs the logic corresponding to the read control logic information, and outputs the result of the performed logic to another one of the plurality of memory areas.