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											2018-05-29 10:24:28 -05:00
										 |  |  | subroutine extractmessage174_91(decoded,msgreceived,ncrcflag)
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							|  |  |  |   use iso_c_binding, only: c_loc,c_size_t
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							|  |  |  |   use crc
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							|  |  |  |   use packjt
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							|  |  |  | 
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							|  |  |  |   character*22 msgreceived
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							|  |  |  |   character*91 cbits
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							|  |  |  |   integer*1 decoded(91)
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							|  |  |  |   integer*1, target::  i1Dec8BitBytes(12)
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							|  |  |  |   integer*4 i4Dec6BitWords(12)
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							|  |  |  | 
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							|  |  |  | ! Write decoded bits into cbits: 77-bit message plus 14-bit CRC
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							|  |  |  |   write(cbits,1000) decoded
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							|  |  |  | 1000 format(91i1)
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							|  |  |  |   read(cbits,1001) i1Dec8BitBytes
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							|  |  |  | 1001 format(12b8)
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							|  |  |  |   read(cbits,1002) ncrc14                         !Received CRC12
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							|  |  |  | 1002 format(77x,b14)
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							|  |  |  | 
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							|  |  |  |   i1Dec8BitBytes(10)=iand(i1Dec8BitBytes(10),128+64+32+16+8)
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							|  |  |  |   i1Dec8BitBytes(11:12)=0
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							|  |  |  |   icrc14=crc14(c_loc(i1Dec8BitBytes),12)          !CRC12 computed from 75 msg bits
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							|  |  |  | 
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							|  |  |  |   if(ncrc14.eq.icrc14 .or. sum(decoded(57:87)).eq.0) then  !### Kludge ###
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							|  |  |  | ! CRC14 checks out --- unpack 72-bit message
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							|  |  |  |     do ibyte=1,12
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							|  |  |  |       itmp=0
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							|  |  |  |       do ibit=1,6
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							|  |  |  |         itmp=ishft(itmp,1)+iand(1,decoded((ibyte-1)*6+ibit))
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							|  |  |  |       enddo
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							|  |  |  |       i4Dec6BitWords(ibyte)=itmp
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							|  |  |  |     enddo
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											2018-07-11 10:13:42 -04:00
										 |  |  |     call unpackmsg(i4Dec6BitWords,msgreceived)
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											2018-05-29 10:24:28 -05:00
										 |  |  |     ncrcflag=1
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							|  |  |  |   else
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							|  |  |  |     msgreceived=' '
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							|  |  |  |     ncrcflag=-1
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							|  |  |  |   endif 
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							|  |  |  |   return
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							|  |  |  |   end subroutine extractmessage174_91
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