QINSUN interprets the on-site troubleshooting method of the electromagnetic flowmeter-

1. Solution to the problem of inaccurate, unstable and random jump of the measured signal value From the following, it can be seen that the main source of the problem of inaccurate, unstable and random jump of the measured value electromagnetic flowmeter signal value For power frequency interference, the use of synchronous sampling technology can effectively suppress the power frequency interference signal in the measurement signal. Synchronous sampling is also called tracking sampling, i.e., in order to keep the sampling frequency fs in constant relation with the actual operating frequency f1 of the system N=fs/f1, the width of the sampling pulse is several times the power frequency period, so that the flow signal potential The average value of power frequency interference is zero to eliminate the feedback of the interpower frequency references; for random interference signals, digital filtering procedures can be used for processing, and for different interference signals, order discrimination filtering, median filtering and arithmetic mean filtering can be used, the Moving average value filtering, weighted moving average value filtering and other forms of filtering can receive very good results.

 2. Solution to the problem of two-point drift Common-mode interference refers to the interference voltage of the common part on the signal output channel. The overall design of the output channel adopts an unbalanced output form to ground, so the common-mode signal is meshed into the useful signal, resulting in two-point drift. By changing the output mode of the output channel, the single-ended output mode is changed to the output modedouble-ended ungrounded, which is commonly referred to as differential output mode. Through the differential output mode, the interference voltage of common mode interference on the output channel can be eliminated. For elimination, the two-point drift problem caused by common-mode interference can be solved.
As for the two-point drift problem caused by the conditional measurement change, the use of measurement compensation technology has solved this problem well. That is, a conditional measurement detection unit is added in the path, and the detected measurement value is transmitted to the single-chip microcomputer in real time. The single-chip microcomputer compensates for certain parameters of the path based on the change in the measured measurement, which greatly reduces the conditional measurement. Transitions for two-point drifts that occur for paths.

 3. Solutions to crashes and scrambled codes on the spot
As for crashes and scrambled codes caused by uncontrollable programs, the channel for monitoring the operation of the program, namely the watchdog , is added to the channel. It was discovered in time, and the entire system was reset, so that the operation of the program returned to the correct path, avoiding the appearance of crashes and garbled characters.

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