Attempt to add part at undefined sensor 1 on conveyor coneyor001？

dd13616

Attempt to add part at undefined sensor 1 on conveyor coneyor001是怎么回事？
0 y) x/ z9 ~/ u: O7 [+ o
conveyor元素的input rule：
$ T0 Z, x' x1 [, v) q3 A* n9 \if nparts(coneyor001)<5
- y* z" b4 B4 r. w( l* C) Fpull from buf1 with labor1 using path
else
wait
endif