Serial | Fault phenomenon | Possible causes of failure | terms of settlement |
1 | Communication failure | (1) Whether the RTU station address is inconsistent with the address set by the central station; | (1) Reset the address; |
(2) RTU does not work normally; | (2) Replace RTU; |
(3) The antenna direction of RTU radio station is not pointing to the central station; | (3) Adjust the antenna; |
(4) The radio station is not working properly. | (4) Replace the radio station. |
2 | Low communication success rate (large channel interference) | (1) The feeder is not connected properly; | (1) Connect the feeder; |
(2) Large electromagnetic interference near RTU; | (2) Avoid interference; |
(3) RTU has no good ground wire. | (3) Grounding. |
3 | Communication succeeded, but the data is 0 | (1) The instrument has no output; | (1) Check the instrument; |
(2) The central station configuration is inconsistent with the RTU instrument channel; | (2) Calculate the correct coefficient; |
(3) Fault of RTU data acquisition part; | (3) Check the input interface. |
4 | The communication is successful, but the data is inconsistent with the field instrument | (1) Instrument full scale; | Bottom number: (12): 800; |
(2) Setting of base number and coefficient of central station configuration; | Coefficient: instrument full scale / RTU AI full scale. |
(3) Incorrect reference voltage; |
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(4) The input type of AI is inconsistent with the instrument; |
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5 | The communication is successful, but the data jumps | (1) Feeder interference; | (1) Parallel capacitance; |
(2) Large electromagnetic interference near RTU (such as frequency converter); | (2) Avoid interference sources; |
(3) AC power line interferes with 4 ~ 20mA signal. | (3) Separate the wiring. |
6 | RTU crash | (1) RTU watchdog, imperfect software and hardware design | Field reset |
(2) High electromagnetic interference near RTU |
(3) RTU without good ground wire |
7 | Output inoperative | (1) The controlled equipment is damaged and the output electrical surge; | (1) When receiving inductive load (such as motor or relay), it is necessary to use a suppression circuit; |
(2) Loose or incorrect wiring; | (2) Check the wiring. If it is incorrect, correct it; |
(3) Output overload; | (3) Check the load rate of power supply and output; |
(4) There is a problem with the communication cable; | (4) Check whether the CPU of PLC is forced; |
(5) Station address setting error. | (5) Reset the station address; Check the communication cable. |