The pluses comes from coder to send to the high speed counter, and the number of the high speed counter is operated in the program of PLC to get the absolute displacement anticipated.

采用PLC的高速计数器进行测量轮正转和反转时的脉冲信号的采集，通过进一步程序运算得到绝对位移量。

youdao

The Royal Navy minehunter operated out of Bahrain conducting counter-piracy and security patrols as well as exercises with coalition forces.

BBC: HMS Middleton