Digital data processing system with asynchronous sensing units

DETAILED DESCRIPTION In order to overcome the aforementioned drawbacks, the invention provides a digital data processing system of the type which can be used to protect a large-scale analog system such as an electric power system wherein variable parameters such as current or voltage representative of operational states of the system are sampled with a plurality of sensing units located remotely from one another using clock signals in each sensing unit which are asynchronous from unit to unit.
Analog-to-digital converter units in each of the sensing units convert a sensed parameter into digital data at a rate which is higher than expected variations with time of the sensed parameters to provide digital data representative thereof.
The digital data from each sensing unit is transmitted at a high rate to a data processing unit including a data processing device such as a digital computer.
The data from the various sensing units is synchronously sampled and inputted to the digital processing device through a buffer unit which may be implemented with a random access memory.
The digital processing device processes this data using the results to protect the analog system.