如果不能做到这一点，筒子的回转力矩会使它继续转动并退绕纱线，而退绕的纱线不能被卷绕到新卷装上。

If this is not done, the rotational momentum of the spool will cause it to remain in motion allowing yarn to be unwound without being taken up.

youdao

回想一下在络纱过程中，往复导纱机构引导纱线沿着卷装往复一次，完成一个完整的循环。

Recall that, in package winding, the traversing mechanism makes a full cycle in carrying the yarn completely back and forth along the package.

youdao

并且，根据正转脉冲信号的计数值算出 卷绕到卷装（30）上的纱线长度。

Then, based on the count value in the forward rotation pulse signal, the length of the yarn wound into the package 30 is calculated.

youdao