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？
$ {, m0 C/ y' [6 _' E( P% j% S- B/ L/ [
conveyor元素的input rule：
if nparts(coneyor001)<5
pull from buf1 with labor1 using path
* T9 ^% t; M6 N: u8 O" L* O" yelse
wait
endif