referring to fig1 , a measurement system 20 of the present invention is shown in the environment of an aircraft 22 . it will be appreciated by those skilled in the art that measurement system 20 can also be used in other environments that have multiple sensors scattered in a number of locations . for example , measurement system 20 may be used in other vehicular systems , such as ships , trains , space vehicles , tanks , trucks or a complex industrial control system . measurement system 20 includes a bus 24 that interconnects one or more computers 26 and a plurality of rdcs 30 . each rdc 30 is placed in a location that is in the vicinity of a plurality of sensors 32 . these locations may be located near a computer 26 or remote from the computers 26 . computers 26 may be any suitable computers that process data . for example , computer 26 may be a personal computer , a workstation , a large data processor or any system component requiring the sensor data . rdcs 30 are substantially identical ( i . e ., universal ), but are individually configured based on configuration data that may be provided by one or more of computers 26 . that is , the configuration data for each rdc is unique to the set or group of sensors 32 with which the rdc is connected . referring to fig2 , rdc 30 includes a processing unit 40 that is connected with bus 24 via a serial data interface 41 and with a sensor excitation unit 50 and a sensor return signal unit 70 . processing unit 40 includes a digital signal processor 42 , a read only memory ( rom ) 44 and a random access memory ( ram ) 46 . a crystal oscillator 48 provides a clock signal to digital signal processor 42 . sensor excitation signal unit 50 includes a digital to analog converter ( dac ) 52 , a set of amplifiers 54 , electromagnetic interference ( emi ) filters 56 and a set of selector switches 58 . sensor excitation signal unit 50 is arranged to provide excitation signals on a plurality of connectors 60 , 61 , 62 , 63 , 64 , 65 and 66 . to this end , dac 52 converts a digital excitation signal provided by dsp 42 to an analog signal . switches 58 respond to a selector signal from dsp 42 via a line 55 to provide excitation signals on one or more desired connectors . sensor return signal unit 70 includes an analog to digital converter ( adc ) 72 , an input amplifier 74 , a multiplexer 78 and emi filters 76 . sensor return signal unit 70 is arranged to receive sensor return signals on a plurality of channels or connectors 80 , 81 , 82 , 83 , 84 , 85 and 86 . emi filters 76 filter emi from the sensor return signals . multiplexer 78 is controlled via a connection 90 from dsp 42 to select one of the sensor return signals for connection to input amplifier 74 . the amplified sensor return signal is converted from analog to digital by adc 72 for application to dsp 42 at a rate sufficient to characterize the waveform as needed ( i . e . 1 mhz for most applications ) and to accommodate the noise environment . each of connectors 60 - 66 and connectors 80 - 86 is intended for connection with a sensor 32 . for example , connectors 60 and 80 and connectors 61 and 81 are connected in circuit with the sensors designated as s 1 and s 2 , respectively . connectors 60 and 80 form a connector pair and a channel of rdc 30 . connectors 61 and 81 form a connector pair and a channel of rdc 30 . similarly , the remaining connectors 62 - 66 form connector pairs with connectors 82 - 86 , respectively , and channels of rdc 30 . two or more rdc channels can be used to interface to multiple excitation or multiple return type sensors such as linear variable differential transformers ( lvdts )/ rotational variable differential transformers ( rvdts ) and three wire ratiometric sensors , such as some weight / balance sensors . a receiver channel alone ( without excitation ) can be used to measure independently generated signals , such as a flowmeter turbine speed signal or other frequency signal sensors . seven channels are shown by way of example only . it will be appreciated by those skilled in the art that the number of channels chosen for an rdc 30 is dependent on the number of sensors and their locations in a given application as well as trade - offs , such as cost vs . throughput rate , redudancy and other considerations . rdc 30 also includes a power supply 100 that has a regulator 102 to provide regulated voltages to the various components of rdc 30 . rdc 30 optionally includes discrete input / output ( i / o ) circuits 104 for use in providing and receiving simple discrete inputs without using up a standard rdc channel rdc 30 also provides scaling control signals to dac 52 and input amplifier 74 via connections 92 and 94 , respectively . dsp 42 may be any suitable processor , known currently or in the future , and preferably is a digital signal processor that is capable of generating the sensor excitation signals and processing the sensor return signals . for example , dsp 42 may be a texas instruments corporation part number tms320lv5400 . dsp 42 processes discrete fourier transform or fft algorithms in real time to calculate the sensor parameters . dsp 42 also generates the excitation waveform by stuffing dac 52 with look - up table values or calculated values . for the majority of sensor applications , the measurement will be made for the impedance ( inductive , capacitive or resistive ) of the sensor with a sinusoidal excitation of a given frequency . to process the acquisition of any impedance type sensor , dft ( discrete fourier transform ) calculations are done using the dsp mac ( multiply - accumulate ) instructions of dsp 42 to determine the impedance at the given excitation frequency . similar measurements are made on a reference element , which is a high precision resistor in order to calibrate the scaling and to define zero phase for establishing the phase of reactive impedances . referring to fig3 , ram 46 includes a configuration program 116 , a measurement procedure 118 , a configuration data file 110 , which includes a channel assignment file 112 and a sensor configuration file 114 . sensor configuration file 114 lists for each of a plurality of sensor types , designated as a through j , characteristics that are unique to that sensor type . for example , sensor configuration file 114 lists for sensor type a excitation signal parameters , scaling parameters and return signal characteristics . similar characteristics would be listed for sensor types b through j . channel assignment file 112 lists an assignment of sensor type to each channel . for example , channel 60 / 80 is assigned to sensor type a . that is , channel 60 / 80 is connected to a sensor 32 of type a . channel 61 / 81 is connected to a sensor of type b , and so on . alternatively , as described above , two channels can be used to interface to multiple excitation or multiple return signal sensor types , or a single input channel used for non - excitation signals . configuration data 110 can be downloaded to rdc 30 from one or more of computers 26 upon power up of measurement system 20 or at any other suitable time . alternatively , a sensor menu configuration table 114 could be programmed into rom 44 . this would avoid downloading thereof , thus avoiding use of the bandwidth of bus 24 . dsp 42 runs configuration program 116 to configure rdc 30 for the sensors types that are connected to the channels of rdc 30 based on the configuration data file 110 . when configured for the channels of rdc 30 , dsp 42 generates the desired excitation waveforms ( frequency , amplitude , and wave shape ), measurement circuit scaling parameters and performs discrete sampling of the sensor return signals . that is , rdc 30 provides a common circuit interface type to the sensors 32 . additional dedicated lines 120 provide for discrete logic level signal measurements and discrete outputs for rapid response functions , such as engine overspeed shutdown or dual turboprop autofeather control . dsp 42 runs measurement procedure 118 that uses a sampling procedure or time domain processing procedure to provide precision phase angle and amplitude measurements of ac signals at specific discrete frequencies relative to the sample rate . either of these procedures makes it possible for a single processing solution to provide precision measurements over a broad range of configurable frequencies and amplitudes . the sampling procedure may be a standard discrete fourier transform ( dft ) process or a fast fourier transform ( fft ) process . the dft and fft signal sampling / processing techniques provide a capability to create the general purpose common interface circuit for the rdc . although generally not a cost - effective solution for discrete measurements , an rdc channel may be configured to do so . the time domain processing procedure may be a digital filtering process or a zero crossing detection process . the measurement system and method of the present invention provides multiplexed multi - channel operation to support multiple sensor technologies , including but not limited to : two or three wire proximity ( inductive ) sensors , two or three wire capacitive ( i . e ., fuel gauging ), lvdts , rvdts , synchros , strain sensors , temperature and pressure sensors , engine speed sensors , monopole torque sensors and the like . the method of the present invention provides to each of a plurality of substantially identical rdcs 30 a configuration data file that is unique to that rdc and configures each rdc based on its unique configuration data file : the method additionally runs on each rdc 30 a measurement procedure 118 based on the configuration thereof . for example , standard sampling theory methods are preferably used to determine the desired information from the sampled data . as an example , for measurement of a honeywell proximity sensor , two separate measurements are made — the impedance when excited with a 2 khz sinusoidal excitation at 1v rms , and then with a 6 khz sinusoidal excitation at 1v rms . at one or two microsecond intervals the following occur for a period of 1 ms . 1 ) a new excitation is written to excitation dac 52 , 2 ) the excitation and sensor return signal are sampled simultaneously , and 3 ) the samples are used to update four mac ( multiply - accumulate ) sums needed to calculate the dft of the return signal at the frequency of excitation . the four mac sums are the sine and cosine mac sums performed on both the excitation and the sensor return signal samples . at the end of the acquisition period the dft calculations are completed to determine the content ( phase and amplitude ) of the sensor signal with respect to that of a reference resistor 122 or 124 ( fig2 ). the impedance is then determined by relative comparison of the phase and amplitude between the reference resistor and the sensor . the sensor impedance and diagnostic data are then stored for transmission on bus 24 . the present invention having been thus described with particular reference to the preferred forms thereof , it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the present invention as defined in the appended claims .