Dc power control is generally divided into local control and external program control. Some applications for system integration and automated testing generally require external program control.

 

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Dc power is generally panel local operation, some low-end resistance potentiometer is used to adjust the voltage and current, LED digital tube to display the voltage and current, some high-end using digital encoder, function button and button combinations to adjust parameters such as voltage and current, generally USES, VFDS, OLED and LCD touch screen to display voltage and current, Some can also display power, working time and other parameters, and increase the ability of external program control.

External program control function is divided into analog and digital program control two ways: usually more commonly used is 0-5V or 0-10V voltage signal, 4-20mA current signal, 0-5K or 0-10K resistance signal control and monitoring DC power supply voltage and current; The power supply can be switched on or off in two ways: dry contact signal and high and low level signal. When purchasing, it is necessary to clearly confirm the control logic of the signal, such as whether it is on or off when doing external closure, and usually whether it is on or off when doing high pressure. The analog signal is generally given and received through PLC to achieve, the more signals need PLC routing also requires more, PCL price is determined by the number of signal routes, in some signal occasions to choose PLC control mode is obviously not the best choice, choose digital communication program control will be more economic, Digital signal compared with analog signal anti-interference ability will be better and more accurate.

Digital signal transmission interface is commonly used in RS-232/485, LAN, USB, CAN, etc. Different manufacturers have different definitions of communication protocols for DC power supplies, including vendor defined protocols and industry standard protocols. At present, the industry standard protocol has a programmable dc power supply industry standard standard command and MOdbus RTU industrial automation instrument, because each customer the protocol used is different, so need to confirm before buying good, especially the system adopts PLC touch screen, touch screen only support the MOdbus protocol, other protocol does not support is unable to communicate, To ensure the versatility of DC power supply, personal brand power supply is compatible with two standard protocols, users can choose the protocol standards according to their own needs through the panel menu operation.