The instrument suddenly reached its maximum value and then returned to normal after 1 second
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This post was last edited by The Passing Years_KKRQ on 2019-2-18 21:37. Control is carried out using a Siemens 300, with a total of over ten instruments. Among them, five instruments of two types suddenly went from their measured values to the maximum range, and then returned to those measured values after 1 second; however, the actual measured values cannot reach the maximum range. For example, if the actual temperature is 260 degrees, it suddenly shows 1100 degrees on the computer, which is the maximum reading; one second later, it returns to 260 degrees. What causes this? Interference? Please ask an expert to help analyze it. The signal from the instrument is 4-20 milliamps. In over half a year, only one case has been detected so far.
I’m not sure if my explanation is clear; I hope experts can give some advice
It’s haunted! Happy Lantern Festival,,, Verification complete. . :lol
For such issues, first check the cable connections and for any static interference: lol
During self-check, electronic instruments will sweep through their entire range to prove that the instrument and its wiring are functioning properly. However, in the case of LZ, it seems to be in use at the time. Self-check is usually carried out once at the start of use; under normal conditions with no human interference or power outages, such issues have not been encountered. It’s certain that the wiring is connected and the instrument is working fine – the problem is simply some kind of interference. What #4 mentioned about static electricity interference is a possibility.
Is the thread loose? It suddenly reached full scale... but it’s unlikely; this happened only once with yours
Interference and power supply current fluctuations, or poor grounding; if it’s on the same card, there may also be communication issues with that card
Two types, several channels – how many tables in total? Are they connected through the same card? If so, it’s very likely that the problem lies with that card
First, secure all the connection points in the circuit to check for any loose connections; if there are still issues after securing them, then it’s time to look into hardware problems
Whether it has been struck by lightning or subjected to strong electrical interference.
Check the path taken by these return cables to see if there are strong magnetic fields or significant interference in that area; for example, high-pressure pumps or locations near high-voltage rooms can cause such issues. Also, when this phenomenon occurs, note which electrical devices were turned on at that moment. I don’t think it’s likely that there’s a fault with the PLC card itself; you can simply try using a new card