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？

conveyor元素的input rule：
if nparts(coneyor001)<5
2 B2 [/ B. ~' H# |pull from buf1 with labor1 using path
' w6 T, S7 K+ p) n/ H: l* L) t6 gelse
" ~0 J$ M' [. q7 s* I) swait
1 H, m8 e/ f; V' O1 @endif