请教各位:在三菱PLC控制伺服电机时,有时需要原点回归,但在原点回归指令ZRN时却没有指定运行方向,但是当伺服处于原点的负方向时,它应该正转回归原点;当伺服处于原点的正方向时,它应该反转回归原点.是否在运行过程中伺服电机能判断在启动时的初始位置在原点的正反方向?

请问版主如果是控制步进电机 ，只用一个光电开关回原点怎么做
如图
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