This part of the IEC 62453-51-xy series, which is a Technical Report, provides information for integrating IEC 61784-2 CPF 15 (Modbus TCP) and Modbus Serial Line1 protocol support into FDT systems based on COM implementation. This part is to be used in conjunction with IEC TR 62453-41. NOTE This part of IEC 62453 only specifies the mapping of Modbus parameters to FDT data types. For restrictions of protocol specific parameters concerning allowed values and concerning limitations of arrays used in the definition of FDT data types, refer to IEC 61158-5-15 and the MODBUS Application Protocol Specification. This part of IEC 62453 specifies the implementation of communication and other services based on IEC 62453-315. This document neither contains the FDT specification nor modifies it.