Processing of power supply by PLC 

Power supply is one of the main ways for interference to enter the programmable controller. Power supply interference is mainly generated by impedance coupling of power supply lines, and various high-power electrical equipment is the main source of interference.

In situations with strong interference or high reliability requirements. A shielded isolation transformer and a low-pass filter can be added to the AC power input( Allen Bradley 1794-IB16 Flex Input Module, B&R X20BM05 Bus Module, Siemens 6ES7132-4BD02-0AA0 ET 200S Electronic Module,  Allen Bradley 1734-OB8 Output Module) end of the programmable controller (see Figure 1). The isolation transformer can prevent external interference from the power line. To improve the ability to resist high frequency common mode interference, the shielding layer should be grounded reliably.

he external DC power supply for the external input circuit should preferably be a stable power supply. The power supply that only rectifies and filters the AC voltage contains strong ripples, which may cause the programmable controller to receive wrong information.

The interested persons of mentioned parts may relate with me, price liberally. --

Vivi (sh_plc@163.com).