spacewire.F90 25.6 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763
!
! This file is part of SACAMOS, State of the Art CAble MOdels in Spice. 
! It was developed by the University of Nottingham and the Netherlands Aerospace 
! Centre (NLR) for ESA under contract number 4000112765/14/NL/HK.
! 
! Copyright (C) 2016-2017 University of Nottingham
! 
! SACAMOS is free software: you can redistribute it and/or modify it under the 
! terms of the GNU General Public License as published by the Free Software 
! Foundation, either version 3 of the License, or (at your option) any later 
! version.
! 
! SACAMOS is distributed in the hope that it will be useful, but 
! WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
! or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License 
! for more details.
! 
! A copy of the GNU General Public License version 3 can be found in the 
! file GNU_GPL_v3 in the root or at <http://www.gnu.org/licenses/>.
! 
! SACAMOS uses the EISPACK library (in /SRC/EISPACK). EISPACK is subject to 
! the GNU Lesser General Public License. A copy of the GNU Lesser General Public 
! License version can be found in the file GNU_LGPL in the root of EISPACK 
! (/SRC/EISPACK ) or at <http://www.gnu.org/licenses/>.
! 
! The University of Nottingham can be contacted at: ggiemr@nottingham.ac.uk
!
! File Contents:
! SUBROUTINE spacewire_set_parameters
! SUBROUTINE spacewire_set_internal_domain_information
! SUBROUTINE spacewire_plot
!
! NAME
!     spacewire_set_parameters
!
! AUTHORS
!     Chris Smartt
!
! DESCRIPTION
!     Set the overall parameters for a spacewire cable
!
! COMMENTS
!      
!
! HISTORY
!
!     started 5/9/2016 CJS based on spacewire.F90
!     16/11/2017 CJS Include network synthesis process to replace s-domain transfer functions
!
!
SUBROUTINE spacewire_set_parameters(cable)

USE type_specifications

IMPLICIT NONE

! variables passed to subroutine

  type(cable_specification_type),intent(INOUT)    :: cable

! local variables

! START

  cable%cable_type=cable_geometry_type_spacewire
  cable%tot_n_conductors=13
  cable%tot_n_domains=10
  cable%n_external_conductors=1
  cable%n_internal_conductors=12
  cable%n_internal_domains=9
  cable%n_parameters=13
  cable%n_dielectric_filters=3
  cable%n_transfer_impedance_models=2

END SUBROUTINE spacewire_set_parameters
!
! NAME
!     spacewire_set_internal_domain_information
!
! AUTHORS
!     Chris Smartt
!
! DESCRIPTION
!     Set the overall parameters for a spacewire cable
!
! COMMENTS
!     Set the dimension of the domain transformation matrices to include an external reference conductor for the cable 
!      
!
! HISTORY
!
!     started 12/4/201 CJS 
!     8/9/2016 CJS common mode/ differential mode loss correction
!     19/9/2016 CJS frequency dependent dielectric in Laplace solver
!     2/11/2016 CJS inhomogeneous dielectric in twisted pair model
!     8/5/2017         CJS: Include references to Theory_Manual
!
!
SUBROUTINE spacewire_set_internal_domain_information(cable)

USE type_specifications
USE constants
USE general_module
USE maths
USE PUL_parameter_module

IMPLICIT NONE


! variables passed to subroutine

  type(cable_specification_type),intent(INOUT)    :: cable

! local variables

  integer :: n_conductors
  integer :: dim

  integer  :: domain
  integer  :: inner_cable
  real(dp) :: d,ctheta

  real(dp) :: L11,L12,L13
  real(dp) :: C11,C12
  
  real(dp) :: LC,LD,CC,CD
  logical  :: dielectric_is_homogeneous
  
  integer  :: conductor_1,conductor_2,reference_conductor
  integer  :: diff,com,inner_shield,outer_shield
 
  type(PUL_type)    :: PUL
  
  real(dp) :: C_air
  type(Sfilter) :: jw
 
  integer :: ierr,i
  
  real(dp) :: epsr
 
! variables for cable parameter checks 
  logical :: cable_spec_error

  real(dp) :: rw
  real(dp) :: rd
  real(dp) :: s
  real(dp) :: rs
  real(dp) :: rd2
  real(dp) :: stpr
  real(dp) :: rs2
  real(dp) :: rd3
  real(dp) :: t1
  real(dp) :: t2
  real(dp) :: sigma_w
  real(dp) :: sigma_s1
  real(dp) :: sigma_s2

  type(Sfilter) :: epsr1,epsr2,epsr3,ZT1,ZT2
  type(Sfilter) :: YC,YD
  
  character(LEN=error_message_length) :: message 
  
! START

! Check the cable parameters

  rw=cable%parameters(1)
  rd=cable%parameters(2)
  s=cable%parameters(3)
  rs=cable%parameters(4)
  t1=cable%parameters(5)  
  rd2=cable%parameters(6)
  stpr=cable%parameters(7)
  rs2=cable%parameters(8)
  t2=cable%parameters(9)  
  rd3=cable%parameters(10)
  
  sigma_w=cable%parameters(11)
  sigma_s1=cable%parameters(12)
  sigma_s2=cable%parameters(13)
  
  epsr1=cable%dielectric_filter(1)
  epsr2=cable%dielectric_filter(2)
  epsr3=cable%dielectric_filter(3)
  ZT1=cable%transfer_impedance(1)
  ZT2=cable%transfer_impedance(2)
  
  write(*,*)'CHECKING FOR ERRORS'
  
  cable_spec_error=.FALSE.    ! assume no errors initially
  message=''
  CALL spacewire_check(rw,rd,s,rs,rd2,stpr,rs2,rd3,cable_spec_error,cable%cable_name,message)
  CALL conductivity_check(sigma_w,cable_spec_error,cable%cable_name,message)
  CALL conductivity_check(sigma_s1,cable_spec_error,cable%cable_name,message)
  CALL conductivity_check(sigma_s2,cable_spec_error,cable%cable_name,message)
  CALL dielectric_check(epsr1,cable_spec_error,cable%cable_name,message)
  CALL dielectric_check(epsr2,cable_spec_error,cable%cable_name,message)
  CALL dielectric_check(epsr3,cable_spec_error,cable%cable_name,message)
  CALL transfer_impedance_check(ZT1,cable_spec_error,cable%cable_name,message)
  CALL transfer_impedance_check(ZT2,cable_spec_error,cable%cable_name,message)
  CALL surface_impedance_check(ZT1,sigma_s1,rs,t1,cable_spec_error,cable%cable_name,message)
  CALL surface_impedance_check(ZT2,sigma_s2,rs2,t2,cable_spec_error,cable%cable_name,message)
    
  if (cable_spec_error) then       
    run_status='ERROR in cable_model_builder, error on parameters for cable:'//trim(cable%cable_name)//'. '//trim(message)
    CALL write_program_status()
    STOP 1
  end if
  
  write(*,*)'Use laplace=',use_laplace
  
! pre-calculate inductance matrix elements for two conductors in a cylindrical shield
! See C.R. Paul, 1st edition, equation 3.67a,b with cos(thetaij)=-1

  epsr=evaluate_Sfilter_high_frequency_limit(cable%dielectric_filter(1))
  
  jw=jwA_filter(1d0)
  
  domain=1

  if (use_laplace) then
  
! allocate memory for the PUL parameter solver interface

    if(verbose) write(*,*)'Domain:',domain
    if(verbose) write(*,*)'Allocating PUL data structure for shielded twisted pairs'
    n_conductors=3
    
    CALL allocate_and_reset_PUL_data(PUL,n_conductors)
    
    PUL%shape(1:n_conductors)=circle
    
    PUL%x(1)=-s/2d0
    PUL%y(1)=0.0
    PUL%r(1)=rw
    PUL%rd(1)=rd
    PUL%epsr(1)=epsr1
    
    PUL%x(2)=s/2d0
    PUL%y(2)=0.0
    PUL%r(2)=rw
    PUL%rd(2)=rd
    PUL%epsr(2)=epsr1
    
    PUL%epsr_background = 1d0  ! permittivity of homogeneous dielectric medium surrounding the insulated conductors (air)
  
! no ground plane
    PUL%ground_plane_present=.FALSE.
      
! add overshield i.e. the twinax shield
    PUL%overshield_present=.TRUE.
    PUL%overshield_x = 0d0          ! shield is centred at the origin in this calculation
    PUL%overshield_y = 0d0
    PUL%overshield_r = rs           ! twinax shield radius
    
    CALL PUL_LC_Laplace(PUL,cable%cable_name,cable%Y_fit_model_order,cable%Y_fit_freq_spec,domain) 

! there may be slight asymmmetry due to meshing so average diagonal and off diagonal elements  
! Theory_Manual_Eqn 3.21
    L11=(PUL%L%mat(1,1)+PUL%L%mat(1,1))/2d0
    L12=(PUL%L%mat(1,2)+PUL%L%mat(2,1))/2d0
    
    C11=(PUL%C%mat(1,1)+PUL%C%mat(1,1))/2d0
    C12=(PUL%C%mat(1,2)+PUL%C%mat(2,1))/2d0
    
    dielectric_is_homogeneous=.FALSE.
    
    CALL shielded_twisted_pair_cm_dm_parameter_calculation(L11,L12,C11,C12,epsr,LC,LD,CC,CD,dielectric_is_homogeneous)    
 ! Theory_Manual_Eqn 3.22
 
    YD=0.5d0*( PUL%Yfilter%sfilter_mat(1,1)+((-1d0)*PUL%Yfilter%sfilter_mat(1,2)) )
    YC=2.0d0*( PUL%Yfilter%sfilter_mat(1,1)+PUL%Yfilter%sfilter_mat(1,2) )          
    
  else

! See C.R. Paul, 1st edition, equation 3.67a,b with cos(thetaij)=-1 ! Theory_Manual_Eqn 2.27, 2.28

    L11=(mu0/(2d0*pi))*log( (rs**2-(s/2d0)**2)/(rs*rw) )
    L12=(mu0/(2d0*pi))*log( (s/(2d0*rs)) * (rs**2+(s/2d0)**2)/(2d0*(s/2d0)**2) )
    
    dielectric_is_homogeneous=.TRUE.
    
    CALL shielded_twisted_pair_cm_dm_parameter_calculation(L11,L12,C11,C12,epsr,LC,LD,CC,CD,dielectric_is_homogeneous)    

    YD=CD*jw
    YC=CC*jw
    
  end if  
  
  if (use_laplace) CALL deallocate_PUL_data(PUL)  ! deallocate the PUL data structure
  
  domain=0
  
  do inner_cable=1,4
    
! DOMAIN 1 of this sub-cable: Set the parameters for the internal differential mode domain  
    domain=domain+1
    
    cable%n_internal_conductors_in_domain(domain)=2
    
! The number of modes in the internal differential mode domain is 1

    dim=1
    cable%L_domain(domain)%dim=dim
    ALLOCATE(cable%L_domain(domain)%mat(dim,dim))
    cable%C_domain(domain)%dim=dim
    ALLOCATE(cable%C_domain(domain)%mat(dim,dim))
  
    cable%Z_domain(domain)%dim=dim
    ALLOCATE(cable%Z_domain(domain)%sfilter_mat(dim,dim))
    cable%Y_domain(domain)%dim=dim
    ALLOCATE(cable%Y_domain(domain)%sfilter_mat(dim,dim))
 
    cable%L_domain(domain)%mat(1,1)=LD 
    cable%Z_domain(domain)%sfilter_mat(1,1)=cable%L_domain(domain)%mat(1,1)*jw
  
    cable%C_domain(domain)%mat(1,1)=CD
    cable%Y_domain(domain)%sfilter_mat(1,1)=YD
           
! DOMAIN 2 of this sub-cable: Set the parameters for the internal common mode domain  
    domain=domain+1
    
    cable%n_internal_conductors_in_domain(domain)=2
    
! The number of modes in the internal common mode domain is 2

    dim=1
    cable%L_domain(domain)%dim=dim
    ALLOCATE(cable%L_domain(domain)%mat(dim,dim))
    cable%C_domain(domain)%dim=dim
    ALLOCATE(cable%C_domain(domain)%mat(dim,dim))
  
    cable%Z_domain(domain)%dim=dim
    ALLOCATE(cable%Z_domain(domain)%sfilter_mat(dim,dim))
    cable%Y_domain(domain)%dim=dim
    ALLOCATE(cable%Y_domain(domain)%sfilter_mat(dim,dim))

    cable%L_domain(domain)%mat(1,1)=LC 
    cable%Z_domain(domain)%sfilter_mat(1,1)=cable%L_domain(domain)%mat(1,1)*jw
  
    cable%C_domain(domain)%mat(1,1)=CC
    cable%Y_domain(domain)%sfilter_mat(1,1)=YC
  
  end do ! next inner cable 
   
! now set the parameters for the domain consisting of the outer shield and shields of the inner cables
  domain=domain+1
      
  cable%n_internal_conductors_in_domain(domain)=5
! The number of modes in this domain is 4
  dim=4
  cable%L_domain(domain)%dim=dim
  ALLOCATE(cable%L_domain(domain)%mat(dim,dim))
  cable%C_domain(domain)%dim=dim
  ALLOCATE(cable%C_domain(domain)%mat(dim,dim))
  
  cable%Z_domain(domain)%dim=dim
  ALLOCATE(cable%Z_domain(domain)%sfilter_mat(dim,dim))
  cable%Y_domain(domain)%dim=dim
  ALLOCATE(cable%Y_domain(domain)%sfilter_mat(dim,dim))

! get the parameters for this domain

  d=stpr       ! radius on which the centres of the 4 shielded twisted pairs sit
  epsr=evaluate_Sfilter_high_frequency_limit(epsr2)    ! 

  if (use_laplace) then
  
! allocate memory for the PUL parameter solver interface

    if(verbose) write(*,*)'Domain:',domain
    if(verbose) write(*,*)'Allocating PUL data structure for shielded twisted pairs'
    n_conductors=5
    
    CALL allocate_and_reset_PUL_data(PUL,n_conductors)

    PUL%shape(1:n_conductors)=circle
    
    PUL%x(1)=stpr
    PUL%y(1)=0.0
    PUL%r(1)=rs
    PUL%rd(1)=rd2
    PUL%epsr(1)=epsr2 ! permittivity of frequency dependent dielectric medium surrounding conductors
    
    PUL%x(2)=0.0
    PUL%y(2)=stpr
    PUL%r(2)=rs
    PUL%rd(2)=rd2
    PUL%epsr(2)=epsr2 ! permittivity of frequency dependent dielectric medium surrounding conductors
    
    PUL%x(3)=-stpr
    PUL%y(3)=0.0
    PUL%r(3)=rs
    PUL%rd(3)=rd2
    PUL%epsr(3)=epsr2 ! permittivity of frequency dependent dielectric medium surrounding conductors
    
    PUL%x(4)=0.0
    PUL%y(4)=-stpr
    PUL%r(4)=rs
    PUL%rd(4)=rd2
    PUL%epsr(4)=epsr2 ! permittivity of frequency dependent dielectric medium surrounding conductors

    PUL%epsr_background =1d0 ! permittivity of homogeneous medium surrounding the insulated shields (air)

! no ground plane
    PUL%ground_plane_present=.FALSE.
      
! add overshield i.e. the twinax shield
    PUL%overshield_present=.TRUE.
    PUL%overshield_x = 0d0          ! shield is centred at the origin in this calculation
    PUL%overshield_y = 0d0
    PUL%overshield_r = rs2           ! twisted pair shield radius
    
    CALL PUL_LC_Laplace(PUL,cable%cable_name,cable%Y_fit_model_order,cable%Y_fit_freq_spec,domain) 
       
    cable%L_domain(domain)%mat(:,:)=PUL%L%mat(:,:)
    cable%C_domain(domain)%mat(:,:)=PUL%C%mat(:,:)
    
    cable%Z_domain(domain)%sfilter_mat(:,:)=PUL%Zfilter%sfilter_mat(:,:)
    cable%Y_domain(domain)%sfilter_mat(:,:)=PUL%Yfilter%sfilter_mat(:,:)
    
  else

! See C.R. Paul, 1st edition, equation 3.67a,b ! Theory_Manual_Eqn 2.27, 2.28
! self inductance
    L11=(mu0/(2d0*pi))*log( (rs2**2-d**2)/(rs2*rs) )
  
! adjacent conductors, theta=90degrees, cos(theta)=0
    ctheta=0
    L12=(mu0/(2d0*pi))*log( (d/(rs2)) * &
         sqrt(  ((d*d)**2+rs2**4-2d0*d*d*rs2*rs2*ctheta)/((d*d)**2+d**4-2d0*(d**4)*ctheta)  ) )
  
! opposite conductors, theta=180 degrees, cos(theta)=-1
    ctheta=-1d0
    L13=(mu0/(2d0*pi))*log( (d/(rs2)) *  &
        sqrt(  ((d*d)**2+rs2**4-2d0*d*d*rs2*rs2*ctheta)/((d*d)**2+d**4-2d0*(d**4)*ctheta)  ) )

    cable%L_domain(domain)%mat(1,1)=L11
    cable%L_domain(domain)%mat(1,2)=L12
    cable%L_domain(domain)%mat(1,3)=L13
    cable%L_domain(domain)%mat(1,4)=L12
  
    cable%L_domain(domain)%mat(2,1)=L12
    cable%L_domain(domain)%mat(2,2)=L11
    cable%L_domain(domain)%mat(2,3)=L12
    cable%L_domain(domain)%mat(2,4)=L13
  
    cable%L_domain(domain)%mat(3,1)=L13
    cable%L_domain(domain)%mat(3,2)=L12
    cable%L_domain(domain)%mat(3,3)=L11
    cable%L_domain(domain)%mat(3,4)=L12
  
    cable%L_domain(domain)%mat(4,1)=L12
    cable%L_domain(domain)%mat(4,2)=L13
    cable%L_domain(domain)%mat(4,3)=L12
    cable%L_domain(domain)%mat(4,4)=L11
    
! calculate the capacitance matrix from the inverse of the inductance matrix *eps0*epsr*mu0

    ierr=0   ! set ierr=0 on input to matrix inverse to cause the program to stop if we have a singular matrix
    CALL  dinvert_Gauss_Jordan(cable%L_domain(domain)%mat,4,cable%C_domain(domain)%mat,4,ierr)
    cable%C_domain(domain)%mat(:,:)=eps0*epsr*mu0*cable%C_domain(domain)%mat(:,:)  
   
    CALL Z_Y_from_L_C(cable%L_domain(domain),cable%C_domain(domain),cable%Z_domain(domain),cable%Y_domain(domain))
      
  end if    

  if (use_laplace) CALL deallocate_PUL_data(PUL)  ! deallocate the PUL data structure
  
! Set the domain decomposition matrices ! Theory_Manual_Eqn 6.13, 6.14

! The dimension of the domain transformation matrices is 14
  dim=14
  cable%MI%dim=dim
  ALLOCATE(cable%MI%mat(dim,dim))
  cable%MV%dim=dim
  ALLOCATE(cable%MV%mat(dim,dim))
  
  cable%MI%mat(1:dim,1:dim)=0d0
  cable%MV%mat(1:dim,1:dim)=0d0

! domain decomposition for the 4 sheilded twisted pair cables  
  do inner_cable=1,4
  
    conductor_1=2*(inner_cable-1)+1
    conductor_2=conductor_1+1
    
    diff=2*(inner_cable-1)+1
    com=diff+1
    inner_shield=8+inner_cable
    
    cable%MI%mat(diff,conductor_1)=0.5d0
    cable%MI%mat(diff,conductor_2)=-0.5d0
    
    cable%MI%mat(com,conductor_1)=1d0
    cable%MI%mat(com,conductor_2)=1d0
    
    cable%MV%mat(diff,conductor_1)=1d0
    cable%MV%mat(diff,conductor_2)=-1d0
    
    cable%MV%mat(com,conductor_1)=0.5d0
    cable%MV%mat(com,conductor_2)=0.5d0
    cable%MV%mat(com,inner_shield)=-1d0
    
  end do
  
! domain decomposition for the domain between outer shield and twisted pair shields

  outer_shield=13

  do inner_cable=1,4
  
    conductor_1=2*(inner_cable-1)+1
    conductor_2=conductor_1+1
    inner_shield=8+inner_cable
    
    cable%MI%mat(inner_shield,conductor_1)=1d0
    cable%MI%mat(inner_shield,conductor_2)=1d0
    cable%MI%mat(inner_shield,inner_shield)=1d0
    
    cable%MV%mat(inner_shield,inner_shield)=1d0
    cable%MV%mat(inner_shield,outer_shield)=-1d0
    
  end do
  
! domain decomposition for the external domain conductor.

  cable%MI%mat(13,1:13)=1d0
  
  cable%MV%mat(13,13)=1d0
  cable%MV%mat(13,14)=-1d0

! domain decomposition for the reference domain conductor. Outer shield current is equal to the sum of all other currents
  cable%MI%mat(14,1:14)=1d0
  
  cable%MV%mat(14,14)=1d0

! Set the local reference conductor numbering  
  ALLOCATE( cable%local_reference_conductor(13) )
  cable%local_reference_conductor(1)=2      ! differential mode, reference is the second conductor
  cable%local_reference_conductor(2)=9      ! common mode, reference is the local shield conductor
  cable%local_reference_conductor(3)=3      ! differential mode, reference is the second conductor
  cable%local_reference_conductor(4)=10     ! common mode, reference is the local shield conductor
  cable%local_reference_conductor(5)=4      ! differential mode, reference is the second conductor
  cable%local_reference_conductor(6)=11     ! common mode, reference is the local shield conductor
  cable%local_reference_conductor(7)=5      ! differential mode, reference is the second conductor
  cable%local_reference_conductor(8)=12     ! common mode, reference is the local shield conductor

  cable%local_reference_conductor(9)=13     ! domain within outer shield, reference is the outer shield conductor
  cable%local_reference_conductor(10)=13    ! domain within outer shield, reference is the outer shield conductor
  cable%local_reference_conductor(11)=13    ! domain within outer shield, reference is the outer shield conductor
  cable%local_reference_conductor(12)=13    ! domain within outer shield, reference is the outer shield conductor
 
  cable%local_reference_conductor(13)=0      ! external domain conductor, reference not known

! Set the local domain information: include a reference conductor in the count
  ALLOCATE( cable%local_domain_n_conductors(1:cable%tot_n_domains) )
  cable%local_domain_n_conductors(1)=2              ! differential mode domain 
  cable%local_domain_n_conductors(2)=2              ! common mode: reference in external domain 
  cable%local_domain_n_conductors(3)=2              ! differential mode domain 
  cable%local_domain_n_conductors(4)=2              ! common mode: reference in external domain 
  cable%local_domain_n_conductors(5)=2              ! differential mode domain 
  cable%local_domain_n_conductors(6)=2              ! common mode: reference in external domain 
  cable%local_domain_n_conductors(7)=2              ! differential mode domain 
  cable%local_domain_n_conductors(8)=2              ! common mode: reference in external domain 
  cable%local_domain_n_conductors(9)=5              ! domain within outer shield
  cable%local_domain_n_conductors(10)=2             ! external domain 
  
! Set the external domain conductor and dielectric information
   
  ALLOCATE( cable%external_model(cable%n_external_conductors) )
  CALL reset_external_conductor_model(cable%external_model(1))
  cable%external_model(1)%conductor_type=circle
  cable%external_model(1)%conductor_radius=rs2
  cable%external_model(1)%dielectric_radius=rd3
  cable%external_model(1)%dielectric_epsr=epsr3 
      
! set the conductor impedance model for the four pairs of inner conductors
  do i=1,7,2
  
    cable%conductor_impedance(i)%impedance_model_type=impedance_model_type_cylindrical_with_conductivity
    cable%conductor_impedance(i)%radius=rw
    cable%conductor_impedance(i)%conductivity=sigma_w
    cable%conductor_impedance(i)%Resistance_multiplication_factor=1.5d0
    
    cable%conductor_impedance(i+1)%impedance_model_type=impedance_model_type_cylindrical_with_conductivity
    cable%conductor_impedance(i+1)%radius=rw
    cable%conductor_impedance(i+1)%conductivity=sigma_w
    cable%conductor_impedance(i+1)%Resistance_multiplication_factor=0.5d0
    
  end do

! set the conductor impedance model for the four inner shields
  
  do i=9,12
    
    cable%conductor_impedance(i)%impedance_model_type=impedance_model_type_cylindrical_shield
    cable%conductor_impedance(i)%radius=rs
    cable%conductor_impedance(i)%thickness=t1
    cable%conductor_impedance(i)%conductivity=sigma_s1
    cable%conductor_impedance(i)%ZT_filter=ZT1
    
  end do
    
! set the transfer impedance model for the outer shield conductor
  
  cable%conductor_impedance(13)%impedance_model_type=impedance_model_type_cylindrical_shield
  cable%conductor_impedance(13)%radius=rs2
  cable%conductor_impedance(13)%thickness=t2
  cable%conductor_impedance(13)%conductivity=sigma_s2
  cable%conductor_impedance(13)%ZT_filter=ZT2
  
! Deallocate all filters   
  CALL deallocate_Sfilter(epsr1)
  CALL deallocate_Sfilter(epsr2)
  CALL deallocate_Sfilter(epsr3)
  CALL deallocate_Sfilter(ZT1)
  CALL deallocate_Sfilter(ZT2)
  CALL deallocate_Sfilter(jw)
  
  ALLOCATE( cable%conductor_label(1:cable%tot_n_conductors) )
  cable%conductor_label(1)='Cable name: '//trim(cable%cable_name)//   &
                           '. type: '//trim(cable%cable_type_string)//'. conductor 1 : Twisted pair 1 wire 1'
  cable%conductor_label(2)='Cable name: '//trim(cable%cable_name)//   &
                           '. type: '//trim(cable%cable_type_string)//'. conductor 2 : Twisted pair 1 wire 2'
  cable%conductor_label(3)='Cable name: '//trim(cable%cable_name)//   &
                           '. type: '//trim(cable%cable_type_string)//'. conductor 3 : Twisted pair 2 wire 1'
  cable%conductor_label(4)='Cable name: '//trim(cable%cable_name)//   &
                           '. type: '//trim(cable%cable_type_string)//'. conductor 4 : Twisted pair 2 wire 2'
  cable%conductor_label(5)='Cable name: '//trim(cable%cable_name)//   &
                           '. type: '//trim(cable%cable_type_string)//'. conductor 5 : Twisted pair 3 wire 1'
  cable%conductor_label(6)='Cable name: '//trim(cable%cable_name)//   &
                           '. type: '//trim(cable%cable_type_string)//'. conductor 6 : Twisted pair 3 wire 2'
  cable%conductor_label(7)='Cable name: '//trim(cable%cable_name)//   &
                           '. type: '//trim(cable%cable_type_string)//'. conductor 7 : Twisted pair 4 wire 1'
  cable%conductor_label(8)='Cable name: '//trim(cable%cable_name)//   &
                           '. type: '//trim(cable%cable_type_string)//'. conductor 8 : Twisted pair 4 wire 2'
  cable%conductor_label(9)='Cable name: '//trim(cable%cable_name)//   &
                           '. type: '//trim(cable%cable_type_string)//'. conductor 9 : Inner Shield 1'
  cable%conductor_label(10)='Cable name: '//trim(cable%cable_name)//   &
                           '. type: '//trim(cable%cable_type_string)//'. conductor 10: Inner Shield 2'
  cable%conductor_label(11)='Cable name: '//trim(cable%cable_name)//   &
                           '. type: '//trim(cable%cable_type_string)//'. conductor 11: Inner Shield 3'
  cable%conductor_label(12)='Cable name: '//trim(cable%cable_name)//   &
                           '. type: '//trim(cable%cable_type_string)//'. conductor 12: Inner Shield 4'
  cable%conductor_label(13)='Cable name: '//trim(cable%cable_name)//   &
                           '. type: '//trim(cable%cable_type_string)//'. conductor 13: Outer Shield'
  
END SUBROUTINE spacewire_set_internal_domain_information
!
! NAME
!     spacewire_plot
!
! AUTHORS
!     Chris Smartt
!
! DESCRIPTION
!     plot spacewire cable 
!
! COMMENTS
!     The angle has an impact here
!     The conductor geometry must be consistent with the documentation...
!
! HISTORY
!
!     started 14/4/2016 CJS 
!
!
SUBROUTINE spacewire_plot(cable,x_offset,y_offset,theta,xmin,xmax,ymin,ymax)

USE type_specifications
USE general_module
USE constants

IMPLICIT NONE

! variables passed to subroutine

  type(cable_specification_type),intent(IN)    :: cable
  
  real(dp),intent(IN) :: x_offset,y_offset,theta
  real(dp),intent(INOUT) ::  xmin,xmax,ymin,ymax

! local variables

  real(dp) :: x,y
  real(dp) :: rw,rd
  real(dp) :: s,rstp
  real(dp) :: xstp,ystp
  real(dp) :: isr         ! inner shield radius
  real(dp) :: idr         ! inner dielectric radius
  real(dp) :: osr         ! outer shield radius
  real(dp) :: odr         ! outer dielectric radius
  
  integer :: inner_cable

! START

  rw=cable%parameters(1)    ! inner conductor radius
  rd=cable%parameters(2)    ! inner conductor dielectric radius
  s=cable%parameters(3)     ! inner conductor separation
  isr=cable%parameters(4)   ! inner shield radius
  idr=cable%parameters(6)   ! inner dielectric radius
  rstp=cable%parameters(7)  ! inner conductor separation
  osr=cable%parameters(8)   ! outer shield radius
  odr=cable%parameters(10)   ! outer dielectric radius

  do inner_cable=1,4

! calculate the centre for this inner cable

    xstp=x_offset+rstp*sin((inner_cable-1)*pi/2d0-theta)
    ystp=y_offset+rstp*cos((inner_cable-1)*pi/2d0-theta)
  
! plot inner conductor, 1
    x=xstp+(s/2d0)*sin(-theta)
    y=ystp+(s/2d0)*cos(-theta)
    CALL write_circle(x,y,rw,conductor_geometry_file_unit,xmin,xmax,ymin,ymax)

! plot inner conductor, 2
    x=xstp-(s/2d0)*sin(-theta)
    y=ystp-(s/2d0)*cos(-theta)
    CALL write_circle(x,y,rw,conductor_geometry_file_unit,xmin,xmax,ymin,ymax)
  
! plot inner conductor dielectric, 1
    x=xstp+(s/2d0)*sin(-theta)
    y=ystp+(s/2d0)*cos(-theta)
    CALL write_circle(x,y,rd,dielectric_geometry_file_unit,xmin,xmax,ymin,ymax)

! plot inner conductor dielectric, 2
    x=xstp-(s/2d0)*sin(-theta)
    y=ystp-(s/2d0)*cos(-theta)
    CALL write_circle(x,y,rd,dielectric_geometry_file_unit,xmin,xmax,ymin,ymax)

! plot shield conductor
    x=xstp
    y=ystp
    CALL write_circle(x,y,isr,conductor_geometry_file_unit,xmin,xmax,ymin,ymax)

! plot circular dielectric
    x=xstp
    y=ystp

    CALL write_circle(x,y,idr,dielectric_geometry_file_unit,xmin,xmax,ymin,ymax)
  
  end do ! next inner cable
  

! plot outer shield conductor
  x=x_offset
  y=y_offset
  CALL write_circle(x,y,osr,conductor_geometry_file_unit,xmin,xmax,ymin,ymax)

! plot outer circular dielectric
  x=x_offset
  y=y_offset

  CALL write_circle(x,y,odr,dielectric_geometry_file_unit,xmin,xmax,ymin,ymax)
  
  RETURN
  
END SUBROUTINE spacewire_plot