In the scheme adopted, the sampling of the various 

 temperature and depth sensors is accomplished by time-sharing 

 multiplexing employing a binary code transmitted along seven 

 electrical conductors extending the length of the cable- 

 The use of a seven-digit binary code allows the use of any 

 number of modules up to 128. The number of modules may be 

 doubled by the addition of another digit,, The electronic 

 equipment for decoding the switching signal, which interro- 

 gates each sensor in turn, is contained in the individual 

 module. The module, when interrogated, transmits a carrier 

 the frequency of which is controlled by its temperature or 

 depth sensor. All power and switching signals are shipboard 

 generated . 



The electronic measurement system thus conforms to the 

 modular concept of the basic cable-and-body vertical sensing 

 array. The number of modules, and hence of measuring points, 

 is variable and essentially unlimited. Modules are completely 



interchangeable (except for an identifying binary number 

 carried on an easily removable coded card) and the type of 

 sensor may be varied from module to module without change in 

 the remainder of the system. 



Figure 14 is a simplified block diagram of a telemetering 

 system which incorporates switching circuits to control the 

 action at each module. Additional features and details are 

 given below in descriptions of the various sub-divisions of 



81 



