德玛机后处理提问

请问用过德玛机的兄弟姐妹 这是德玛机后处理吗？
N1 G30 G17 X-100. Y-100. Z-50.
N2 G31 G90 X100. Y100. Z0.
什么意思啊？
谢谢！

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列出信息创建者：     Administrator
日期                           ： 2009-4-11 15:53:12
当前工作部件              ： F:\jx\2009013 FC(090407)\R1.prt
节点名                      ： ys8
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%R1 G71
; PROGRAM    : R1.i
; PART FILE  : F:\jx\2009013 FC(090407)\R1.prt
; PROGRAMMER : Administrator
; POST DATE  : Sat Apr 11 15:53:14 2009
N1 G30 G17 X-100. Y-100. Z-50.
N2 G31 G90 X100. Y100. Z0.
; PATH NAME  : FACE_MILLING
; TOOL NAME  : D21R0.8  DIA=21.00 R=0.80
N3 T00 G17
N4 S1800 M13
N5 G40 G00 G90 X-220.5 Y+196.143
N6 Z+60.
N7 Z-38.
N8 Z-41.
N9 G01 Z-43. F500.
N10 X-210.5 Y+206.344
N11 X-208.431 Y+208.434 F800.
N12 X-206.341 Y+210.503
N13 X-199.993 Y+210.5
N14 X-184.965
N15 X-187.42 Y+208.317
N16 X-189.849 Y+206.106
N17 X-192.252 Y+203.866
N18 X-194.629 Y+201.598
N19 X-196.979 Y+199.302
N20 X-199.302 Y+196.979
N21 X-201.598 Y+194.629
N22 X-203.866 Y+192.252
N23 X-206.106 Y+189.849
N24 X-208.317 Y+187.42
N25 X-210.5 Y+184.965
N26 Y+162.078
N27 X-208.581 Y+164.54
N28 X-206.634 Y+166.979
N29 X-204.658 Y+169.396
N30 X-202.653 Y+171.788
N31 X-200.621 Y+174.157
N32 X-198.561 Y+176.502
N33 X-196.474 Y+178.823
N34 X-194.359 Y+181.119
N35 X-192.218 Y+183.39
N36 X-190.05 Y+185.636
N37 X-187.856 Y+187.856
N38 X-185.636 Y+190.05
N39 X-183.39 Y+192.218
N40 X-181.119 Y+194.359
N41 X-178.823 Y+196.474
N42 X-176.502 Y+198.561
N43 X-174.157 Y+200.621
N44 X-171.788 Y+202.653
N45 X-169.395 Y+204.658
N46 X-166.979 Y+206.634
N47 X-164.54 Y+208.581
N48 X-162.078 Y+210.5
N49 X-136.931
N50 X-139.504 Y+208.803
N51 X-142.057 Y+207.075
N52 X-144.588 Y+205.316
N53 X-147.097 Y+203.526
N54 X-149.584 Y+201.705
N55 X-152.049 Y+199.854
N56 X-154.49 Y+197.973
N57 X-156.908 Y+196.061
N58 X-159.303 Y+194.121
N59 X-161.674 Y+192.151
N60 X-164.02 Y+190.152
N61 X-166.342 Y+188.124
N62 X-168.638 Y+186.068
N63 X-170.91 Y+183.984
N64 X-173.155 Y+181.873
N65 X-175.374 Y+179.734
N66 X-177.567 Y+177.567
N67 X-179.733 Y+175.375
N68 X-181.873 Y+173.155
N69 X-183.984 Y+170.91
N70 X-186.068 Y+168.639
N71 X-188.124 Y+166.342
N72 X-190.152 Y+164.02
N73 X-192.151 Y+161.674
N74 X-194.121 Y+159.303
N75 X-196.061 Y+156.909
N76 X-197.972 Y+154.49
N77 X-199.854 Y+152.049
N78 X-201.705 Y+149.584
N79 X-203.526 Y+147.097
N80 X-205.316 Y+144.588
N81 X-207.075 Y+142.057
N82 X-208.803 Y+139.505
N83 X-210.5 Y+136.931
N84 Y+107.955
N85 X-209.081 Y+110.678

N1 和 N2那两行 是设定的工件毛坯，（200*200*50的毛坯） 供机器模拟程式用的。

谢谢 gyn-gyn的回答  
但我大的工件是 400X400D的啊
还有我打开.TCL里面有
MOM_output_literal "%[ string toupper $mom_output_file_basename] G71"
MOM_output_literal "; PROGRAM    : [ string toupper $mom_output_file_basename].i"
MOM_output_literal "; PART FILE  : $mom_part_name"
MOM_output_literal "; PROGRAMMER : $mom_logname"
MOM_output_literal "; POST DATE  : $mom_date"
MOM_output_literal "N1 G30 G17 X-100. Y-100. Z-50."
MOM_output_literal "N2 G31 G90 X100. Y100. Z0."

这是后处理里程式头做好了的固定毛坯尺寸，其实不管你工件是什么尺寸都没关系，程式是没有影响的。只是在机床里模拟效果与实际不符，不影响实际加工，如果想要机床上按实际尺寸模拟那让操机人员把那个值手动改成实际毛坯值就好了.

谢谢gyn-gyn