Common software and hardware troubleshooting
1. Common faults and solutions of AI points
AI point is the analog input point. Common faults mainly include IOP -, IOP +, HL, HH, lo, ll and other alarms. When IOP - occurs, it indicates that there is an open circuit alarm in the whole measuring circuit. At this time, the background color of this analog quantity point will turn red and remain unchanged. The treatment method is to check the whole measuring circuit, find the open circuit position and reconnect it. Precautions in the operation process. If this point is a key interlocking point, it should be set to the effective position to avoid J interlocking action caused by large jump in the process of inspection. IOP + alarm indicates that the measurement signal is abnormal, and the signal provided by the field element to DCS cannot be recognized by DCs. The solution to this problem is to check the output signal of the field measurement element to make the output signal meet the access requirements of DCS. There are two possible situations for HL, HH, lo, ll and other alarms. One is that the alarm after signal fluctuation due to process reasons belongs to normal alarm, and the other is that the alarm value setting is unreasonable. At this time, the process workshop needs to give the alarm value again, and the instrument personnel shall cooperate with the alarm change. There is also the problem that the measured value of AI point cannot be consistent with that on the surface. This kind of problem is mainly the problem of range setting. It is enough to ensure the accuracy of range setting. For some flow AI points, there may also be the problem of cumulative quantity, such as the problem of non cumulative value or clearing after exceeding the limit. This kind of problem is mainly to check whether the instrument value is normal and whether the cumulative parameter setting is normal.
2. Common faults and solutions of Ao point
The common fault of Ao point, that is, analog output point, is OOP output open circuit alarm. The phenomenon of this kind of problem is that the control circuit is not controlled. At this time, check the whole Ao circuit in time, find the open circuit point and recover in time. If the card channel is burnt out, replace the channel. If the channel cannot work normally after replacement, replace the Ao card as a whole. The precautions during operation are to switch the measuring circuit controlled by AO point to local control to avoid process fluctuation caused by AO signal fluctuation during inspection. Another common problem is that the Ao card is redundant. In the output circuit of Ao, there is a case of large inductance or load resistance. At this time, the fault is mainly that the redundant card key is stuck. The solution to this kind of problem is to solve the problem of excessive resistance in the control circuit and connect the resistance in the circuit in parallel.
3. Common faults and solutions of DI and do points
The common problems of DI and do points are that the signal is not received or the signal is not sent. The main reasons are software problems and hardware problems. The problem in the software is that the logic setting is incorrect or the logic output channel is wrong. Find the problem and solve it. The hardware problems mainly focus on the damage of card channel, terminal board channel, open circuit of measurement circuit, etc. the solution is to judge the specific fault cause and replace the channel or the card or terminal board.
The above is a detailed introduction about the DCS card of Zhejiang University central control. I hope it will be helpful to you If you have any questions, please contact us We will provide you with professional service http://www.sdjkyqyb.com