Chapter 9 — SPECIALIZED METEOROLOGICAL EQUIPMENT AND THEIR USES 



charts may be displayed simultaneously, super- 

 imposed one over the other. He has the ca- 

 pability of producing a hard copy of displayed 

 data. 



The NEDS contains several significant ad- 

 vantages over all previous NEDN terminals 

 including: 



1. The ability to construct a chart from 

 low speed lines. A typical chart should require 

 less than 10 minutes at 100 wpm teletype rates. 



2. A completely automated receiving terminal. 



3. A soft and hard copy display capability. 



Operation 



The low speed data are received and entered 

 into the teletype interface. The system can op- 

 erate proportionally faster if higher data rates 



are available. The upper limit would be about 

 2400 bits per second, thereby producing a chart 

 every 15 seconds. The interface accumulates the 

 data bits to form characters. The assembled 

 characters are then transferred to the mini 

 computer. The mini computer examines the 

 characters and takes the appropriate action to 

 produce the desired output. Upon completion of 

 the data transmission (typically 10 minutes), 

 the complete chart is displayed on the TV 

 monitor. A hard copy can be made in about 

 15 seconds on the electrostatic plotter. While 

 the data are received, they may be placed on 

 tape for later use if necessary. 



NOTE: Complete details on the NEDS system 

 are not available at this time. Refer to ap- 

 propriate manuals and instructions as they be- 

 come available. 



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