在批量加工箱体、杠杆、盖板类零件时，大多是以工件上一个平面和两定位孔作为定位基准实现组合定位，简称‘一面两孔(一面两销)’定位。
采用‘一面两孔’定位，能使工件在各道工序上的定位基准统一，进而可减少因定位基准多次变换而产生的定位误差，提高工件的加工精度。另外，还可减少夹具结构多样性，便于其设计和制造。
上图指明了面基准所在的位置，标注了两孔位置，其中一个孔只标注了一个轴，属于‘完全定位’。
RationalDMIS 7.1的‘两点偏移队列坐标系机构’可实现‘一面两孔’ 建坐标系功能。
（1）测量立方体前表面，找正第一轴。
（2）测量直径15MM孔和直径20MM孔
（3）XY原点平移到直径15MM孔
（4）两点偏移坐标系
偏移工作平面：指定两孔所在的坐标平面
两点偏移元素设置
完全定位情况如下图，CIR2只限制Z方向，并且位于CIR1的X轴+方向，所以设置如下图：
点击预览，观察坐标系的位置是否正确，再点击添加/激活坐标系.
（5）检查坐标系
打开圆属性页，观察XY实际值是否与图纸标注的一致。
$$/* Header
DMISMN/'Created by [爱科腾瑞科技(北京)有限公司-091520-DEMO] on Monday, April 20, 2020', 4.0
UNITS/MM, ANGDEC, MMPS
WKPLAN/XYPLAN
PRCOMP/ON
TECOMP/ON
FLY/1.0000
MODE/MAN
SNSET/APPRCH, 2.0000
SNSET/RETRCT, 2.0000
SNSET/DEPTH, 0.0000
SNSET/SEARCH, 10.0000
SNSET/CLRSRF, 50.0000
RECALL/D(MCS)
SNSLCT/S(L20-D2.0_A90_B90)
GEOALG/BF, LSTSQR
GEOALG/ANGLB, DEFALT
GEOALG/CIRCLE, LSTSQR
GEOALG/ARC, LSTSQR
GEOALG/PLANE, LSTSQR
$$
$$
$$*/
MODE/MAN
F(PLN1)=FEAT/PLANE,CART,28.9345,0.0000,11.8032,-0.0000,-1.0000,0.0000
$$ Measurement points are created through actual points
MEAS/PLANE, F(PLN1), 4
PTMEAS/CART, -4.9627, -0.0000, 28.7946, -0.0000, -1.0000, 0.0000
PTMEAS/CART, -13.5029, -0.0000, -11.9052, -0.0000, -1.0000, 0.0000
PTMEAS/CART, 64.3956, -0.0000, -10.4777, -0.0000, -1.0000, 0.0000
PTMEAS/CART, 69.8081, -0.0000, 40.8008, -0.0000, -1.0000, 0.0000
ENDMES
D(CRD1) = DATSET/FA(PLN1), -YDIR
D(CRD1) = TRANS/YORIG, FA(PLN1)
F(CIR1)=FEAT/CIRCLE,INNER,CART,-0.0000,2.5920,-0.0000,-0.0000,-1.0000,0.0000, 15.0000
$$ Measurement points are created through actual points
MEAS/CIRCLE, F(CIR1), 4
PTMEAS/CART, -2.5860, 2.5919, 7.0401, 0.3448, -0.0000, -0.9387
PTMEAS/CART, 7.4562, 2.5919, 0.8095, -0.9942, 0.0000, -0.1079
PTMEAS/CART, 0.1782, 2.5919, -7.4979, -0.0238, -0.0000, 0.9997
PTMEAS/CART, -6.7172, 2.5919, -3.3361, 0.8956, -0.0000, 0.4448
ENDMES
F(CIR2)=FEAT/CIRCLE,INNER,CART,50.0000,2.0909,-2.0000,-0.0000,-1.0000,0.0000, 20.0000
$$ Measurement points are created through actual points
MEAS/CIRCLE, F(CIR2), 4
PTMEAS/CART, 48.2299, 2.0908, 7.8421, 0.1770, -0.0000, -0.9842
PTMEAS/CART, 59.9899, 2.0908, -2.4500, -0.9990, 0.0000, 0.0450
PTMEAS/CART, 49.0320, 2.0908, -11.9530, 0.0968, -0.0000, 0.9953
PTMEAS/CART, 40.3746, 2.0908, -4.7116, 0.9625, -0.0000, 0.2712
ENDMES
D(CRD2) = TRANS/XORIG, FA(CIR1), ZORIG, FA(CIR1)
F(CIR1)=FEAT/CIRCLE,INNER,CART,-0.0000,2.5919,0.0000,-0.0000,-1.0000,-0.0000, 15.0000
F(CIR2)=FEAT/CIRCLE,INNER,CART,50.0000,2.0908,-2.0000,-0.0000,-1.0000,-0.0000, 20.0000
D(CRD3) = LOCATE/ZDIR, YAXIS, FA(CIR1), FA(CIR2)
