How to troubleshoot electromagnetic flowmeters in the field? The following points are summarized in our company's many years of use:
1 The processing plan for measuring the signal value is not accurate, there is no steady, and the performance is not
As can be seen from the following, the secondary source for the formation of electromagnetic flowmeter measurement signal value is not accurate, there is no steady, unresponsive jump performance, and the secondary source is the industrial frequency disturbance. After adoption of the argument, the synchronous sampling skill can effectively suppress the power frequency disturbance signal in the measurement signal. Simultaneous sampling is also referred to as tracking sampling. That is, in order to keep the sampling frequency fs always in contrast with the frequency f1 of the fractional practice operation, N=fs/f1, the sampling pulse width is a multiple of the power frequency cycle, making the flow signal potential The uniform value of the power frequency disturbance is equal to zero to eliminate the reaction of the power frequency disturbance; the random disturbance signal can adopt the digital word filtering sequence to stop the solution, and the aligned interference signal can adopt the sequence discrimination filter, the median filter, and the arithmetic uniform value filter. Filtering methods such as gliding uniform value filtering and weighted gliding uniform value filtering can receive very good results.
2 Two-point drift performance plan
Common-mode disturbance refers to the total disturbing voltage on the signal output channel. The general output channel concept assumes a single-ended output to ground, thus forming a common-mode signal that meshes into the useful signal, creating a two-point drift. After changing the output mode of the output channel, the single-ended output format for ground is changed to the double-ended output format that is generally referred to as the differential output format. After the differential output format, the disturbance voltage of the common-mode interference on the output channel is changed. For the cancellation, the common-mode disturbance occurs when the two-point drift occurs.
With regard to the two-point drift performance that results from the change of condition measurement, adopting measures to make up for the skills has made this achievement very poor. In other words, the entire condition measurement measure is being added to the path, and the detected measure value is transmitted to the single-chip microcomputer in real time. The single-chip microcomputer changes the measured value according to the acquired measure, and stops and compensates for some parameters in the path, greatly reducing the condition measurement. Changes are two-point drift for the path.
3 On the spot, we show the processing plan of crashes, garbled scores
With regard to the deadlock and garbled scores resulting from the out-of-order formation, the watchdogs of the sequential operation monitoring path are added in the path, and the performance is detected when the one-chip microcomputer is out of control, and the entire system is reset in time, so that the sequential operation is returned to the accurate trajectory. , to prevent the crash, garbled scores.
So the goods also use the power-off protection skills, hardware training redundancy measures, hardware trap anti-disturbance skills, the adoption of the agency measures also effectively cover the electromagnetic flow meter microcontroller out of control sequence.
Suzhou Gold ant Precision Sheet Metal Co.,Ltd , https://www.jmysheetmetal.com