An intelligent electronic device (IED) is provided. The IED includes a metering sub-assembly and an input base module sub-assembly. The metering sub-assembly is hinged to the input base module sub-assembly, where when in an open position, various cables, connectors, and input/output cards/modules are accessible. Various input/output cards/modules are interchangeable to add/change functionality and/or communication capabilities to the IED. In one embodiment, a communication card is provided with at least one antenna disposed internal or external to a housing of the IED.