There is no exact description of the functions of control inputs. Operation not as described on the housing. Lack of description of electric parameters of counter, e.g. range of trigger voltage levels, maximum counting frequency up and down.
This counter doesn´t work properly. The number 5 wire, that supposed to be the sensor signal, just doesn´t work. Using the blue wire to increase the counting is a workaround, but a lot of missing or double counting occurs when sensor signal is activated. The seller was very kind and tried to understand the problem, but seems the real problem is the bad quality of the product.