P0926GX熱電阻模塊,FOXBORO實驗數據P0926GX
信號程度如果超過規定范圍也會對系統產生影響。為了保證在大型電機進行開關時對系統進行保護,可以采用在電路中加入變壓器,保證在開關電機時不會因為電壓變化過大而產生交變磁場。P0926GX
造成干擾的主要原因?材料及設備問題
接入DCS系統的控制信號通常采用電纜作為傳輸介質將信號送至DCS系統,當信號電纜絕緣材料老化,屏蔽材質損壞,即會被其他電磁干擾源干擾,干擾會造成測量的誤差,嚴重的干擾會造成設備損壞。施工不規范
在DCS控制系統中,往往有很多信號同時接入DCS。這些信號線或者走電纜槽,或者走電纜管,造成現場很多不同種類電纜在同一個路徑附設。這些信號之間均有分布電容存在,會通過這些分布電容將干擾加到別的信號線上。同時,在傳輸信號的周圍環境產生交變的磁通,例如動力線、電動機、發電機、電源變壓器和繼電器等都會產生這種磁場。這些磁場往往會造成較大的干擾。
接地不合理P0926GX熱電阻模塊,FOXBORO實驗數據P0926GX
比較常見的接地事故是信號線的兩端均接地,這樣會因地電勢差而產生較大的干擾。如信號線的兩端同時接地,可能會有較大的電位差,這種電位差可能會在兩端之間的信號線上產生一個很大的環流。產生電磁波,干擾信號。還有DCS系統總接地電阻不符合DCS系統正常工作要求等等。
如何抑制干擾?
保證信號線正常使用
在信號線的使用過程中,避免多條信號線糾纏在一起,同時定期對信號線進行檢查,對有絕緣膠體有破損的信號線進行修復和更換,以保證信號線的正常使用,避免發生漏電而對傳輸信號產生干擾。
將電纜分層敷設peripheral components such as pressure switch and solenoid valve during normal operation of the unit, so as to improve the safety factor of the whole device. Add the memory function of the first cause of the bending machine to help the operators know the first cause of shutdown at the first time, so as to avoid that there are multiple alarm indications on the previous or display panel, and the first cause can not be analyzed, or the first cause can not be found when the indicator light goes out with the instantaneous change of the on-site situation. At the same time, the existence of this function also provides a verification means for the record of accident recall system (SOE). This function can be completed by programming without adding any hardware equipment, and the programming skills are fully applied. When there is no shutdown condition, this function does not need to be executed and does not occupy the time of system monitoring, so that the monitoring and