TwinCAT Scope View 2 demonstration

TwinCAT Scope View 2 demonstration

Below, we show with the aid of the TwinCAT Scope View 2 program how a change of the CoE parameter "Filter Settings" affects the function of the EL3351. The value of this parameter determines the conversion time of the terminal. Due to an entry in the Startup List, the default setting of the example program is 100 Hz, corresponding to a conversion time of 42 ms.

Fig. Scope View 2 Records shows the load/weight (red), the toggle bit (green) and the working counter (blue). The load cell is loaded twice by dropping a coin onto it. From the beginning of the recording to point B the conversion time is 42 ms. The first dropping of the coin takes place at point A. Due to the low filter constant, the actual load curve is recorded only very superficially. At point B the filter is adjusted to 2000 Hz, corresponding to a conversion time of 4 ms. The approx. 10 times more frequent falling and rising edge of the toggle bit can clearly be seen. The second dropping of the coin takes place at point C. The effect of the filter setting on the deflection of the load is clearly visible. Due to the higher conversion time the load exerted on the load cell is measured approx. 10 times more frequently, as a result of which the load curve is recorded with considerably greater precision. At point D communication with the terminal is interrupted, as a result of which the value of the working counter jumps from 0 (valid real-time communication) to 1 (invalid real-time communication).