求助，由于對HLP--B變頻器不熟，特此請教。       變頻器帶電動機正傳-----遇到工件-----停------電機反 轉(zhuǎn)  -----把工件拉回來-----再遇阻力再正轉(zhuǎn)，此過沒有感應器，實現(xiàn)自動正反轉(zhuǎn)。不知如何實現(xiàn)的？                                                                                                                                                                                                                                                                                                                                                

轉(zhuǎn)矩模式，扭矩達到一定值后換相？