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？
+ k5 Y& ]* [3 b0 Q6 s2 Q
conveyor元素的input rule：
& g8 ~' ^+ k9 Z! nif nparts(coneyor001)<5
$ K- X) f& q+ H# Upull from buf1 with labor1 using path
* i0 x! b& F+ `else
# B* |$ V; H' {" {wait
endif