PLC fault finding method and its countermeasures - Database & Sql Blog Articles

RF cable can be customized for other specifications

Programmable Package SG-8018CA(SG7050C) 0.67M~170M

First, plc fault finding flowchart

1, the overall inspection

According to the overall inspection flow chart, find the general direction of the fault point and gradually refine it to find out the specific fault, as shown in Figure 1.

figure 1

2, power failure check

If the power light is off, check the power supply system. The check flow chart is shown in Figure 2.

figure 2

3, running fault check

The power supply is normal and the running indicator is off, indicating that the system has terminated normal operation due to some abnormality. The check flow chart is shown in Figure 3.

image 3

4, input and output fault check

Input and output are the channels through which the PLC communicates with external devices. Whether it works normally or not, in addition to the input and output units, it is also related to the status of components such as connection wiring, terminal blocks, and fuses. The inspection flow chart is shown in Figure 4 and Figure 5.

Figure 4

Figure 5

5. Inspection of the external environment

The environmental factors affecting PLC work mainly include temperature, humidity, noise and dust, as well as corrosive acid and alkali.

Second, programmable controller input and output unit fault handling

Table 1 Programmable controller input unit troubleshooting

Table 2 Programmable Controller Output Unit Troubleshooting