HIMA F3224 digital input module

HIMA F3224 digital input module

The ground wire of the PLC controller control system includes the system ground, ground, alternating ground and protection ground. The disturbance of the grounding system to the PLC controller system is mainly the uneven distribution of potential at each ground point, and the ground potential difference between different ground points, which causes the ground loop current and affects the normal operation of the system. For example, the cable layer must be grounded at one point. If A and B at both ends of the cable layer are grounded, there is a ground potential difference, and a current flows through the layer. When an abnormal state occurs, such as lightning strikes, the ground current will be larger.

All kinds of signal transmission lines connected with the PLC controller control system, in addition to the effective transmission of all kinds of information, there will always be external interference signal intrusion.There are two main ways of this interference: one is through the transmitter power supply or the power supply of the shared signal instrument into the grid interference, which is often ignored; Second, the signal line is interfered by electromagnetic radiation induction in space, that is, the external induction interference on the signal line, which is very serious. The interference introduced by the signal will cause the abnormal work of the I/O signal and the measurement accuracy will be greatly reduced, and the components will be damaged in serious cases. For the system with poor isolation performance, the signals will interfere with each other, causing the bus backflow of the common ground system, resulting in logical data changes, misoperation and crash. PLC controller control system due to signal interference caused by I/O module damage is quite serious, resulting in a lot of system failures.