Patent ID: 8560255

Claim:
An intelligent electronic device (IED), comprising: a housing; a plurality of inputs received at the housing and receiving representations of current or voltage signals from corresponding first current transformers or potential transformers, the first current transformers or potential transformers including a protection current transformer (CT) monitoring a phase of current or voltage and a measurement CT monitoring the same phase of current or voltage as the protection CT, the measurement CT measuring the phase of current or voltage at rated accuracy below a saturation mode of the measurement CT, the protection CT measuring the phase of current or voltage at rated accuracy above the saturation mode of the measurement CT, wherein the plurality of inputs includes a plurality of analog inputs, wherein some of the first transformers are analog transformers that each outputs an analog representation of an analog current or voltage signal sensed by respective ones of the analog transformers, wherein the plurality of inputs include a plurality of digital inputs, wherein others of the first transformers are digital transformers, wherein the representations of current or voltage signals received at the plurality of digital inputs are digital samples representing the current or voltage signals sensed by respective ones of the digital transformers, and wherein the plurality of digital inputs are configured to receive corresponding primary timestamps for each of the digital samples, each of the primary timestamps representing a unique time that each of the digital samples occurred on a primary side of respective ones of the first transformers; a digital conversion unit disposed within the housing, the digital conversion unit converting the analog current or voltage signals from the analog inputs into corresponding digital representations of current or voltage signals from the analog transformers; a power metering unit disposed within the housing, the power metering unit calculating a function that includes a representation of any of the current or voltage signals; a merging unit disposed within the housing, the merging unit being configured to combine the digital representations of the current or voltage signals sensed by the analog and digital transformers into a single set of merged digital samples having a predetermined format, the single set of merged digital samples including the digital representations of the current or voltage signals sensed by the analog and digital transformers; a tagging unit disposed within the housing and that applies a metadata tag to at least some of the representations of current or voltage signals from the analog or digital inputs, wherein the metadata tag includes an indication of the physical analog or digital transformer from which the corresponding received current or voltage signal originated; a memory disposed within the housing, the memory storing the single set of merged digital samples; and a microcontroller coupled to the memory.