The problem of the frequency signals produced by the e+h flow meter to the PLC?
The frequency signal is the pulse, may use the high speed counting module, instantaneous and average, accumulates, these can come out through the software, and has the relation with the time
If PLC uses instantaneous traffic to convert the accumulated traffic, there is usually a 4-20MA output, and this frequency signal is generally used for accumulating. Moreover, the cumulative flow precision of instantaneous flow conversion is much lower than that calculated by pulse counting.
1. The input of the PLC can be a pulse signal, or the analog signal can be converted into a digital signal by the AD module. After the two signals are input, the velocity and flow can be calculated.2. PLC has a memory register, and you should use the cumulative flow that is displayed after the PLC has been accumulated. Even if the power failure, the cumulative flow data remain in the PLC.
There is a flowmeter standard 4-20MA analog signal, the signal is transmitted to the general user PLC to do for the instantaneous flow, some standard meter (or optional) frequency pulse output, a signal is a high level, this signal has two settings: 1, as the instantaneous flow output set the frequency of mode, with the frequency of the size of the instantaneous flow rate corresponding to the (similar to 4-20MA); 2, as the cumulative output, set the pulse mode, defined by a fixed width pulse to represent a fixed flow value (such as 1 pulse signals for 20L), PLC of the pulse number do accumulate, achieve the purpose of flow measurement accumulation.
