What is the use of switching quantities in interface circuits

The switch input signal needs to be electrically isolated in the interface circuit, and in the mechatronics system, the mechanical switch signal is generally a strong current signal, and the strong current part needs to be electrically isolated from the weak current microcomputer system, and the most commonly used is the use of photoelectric coupling.

Do you need any conversion circuits? How to connect the output to the computer? Need a microcontroller? Please give me some tips and guidance, you said that you just came into contact with nothing and don't understand anything, it seems to be true. The switching analog you said should be passed out, first of all.

1. The switching input is the connection channel between the PLC and the detection elements (such as operation control buttons, travel switches, proximity switches, pressure relays, etc.) in the form of switching output, which converts the relevant signals reflecting the production process into digital signals that can be received by the CPU unit.

In order to prevent all kinds of interference and high voltage from entering the PLC and affecting the reliability of PLC operation, electrical isolation and anti-interference measures must be taken. In the industrial site, for various reasons, DC power supply may be used, or AC power supply may be used, and the PLC should provide the corresponding DC input and AC input interfaces.

2. The switching output is a function that realizes the sensor to convert the analog or digital signal sensed to the malfunction into a switching calculation signal, and then outputs it. The general switching output is realized by relays, such as single-throw single pole, single throw double pole, double throw double pole, etc.

Switch: It is a pair of contacts, and there are 2 states between this pair of contacts, either connected, or closed, or disconnected, or open, and the information conveyed by this pair of contacts is a switch. The switching quantity is divided into active or passive, and the active switching quantity will provide a voltage drive while the closed state is closed;

Basis disturbance deficit switching input: It is the connection channel between the PLC and the on-site detection element in the form of switching output, which converts the relevant signal reflecting the failure of the production process into a digital signal that the CPU unit can receive;

Switching output: It is a function that realizes the sensor to convert the analog or digital signal sensed into a switching signal, and then output. The general switching output is realized by relays, such as single throw single pole, single throw double pole, Boshen double throw double pole, etc.

The switching quantity refers to the logical quantity in electrical and electronic engineering, such as a gate knife, which is either turned on or disconnected, and the two must be one of them! The control system must first know the state of the object, for example, there is a door sensory switch, which means that the door is open, then the signal of the door sensor switch is an input (of course, it is a switch), if the door needs to be closed, the system outputs the action command: turn on the power supply of the door motor, which is the output of a switch!

Of course, in addition to switching quantities, we often hear digital, pulse, analog, discrete, and so on.

i o refers to the input and output, i o point 256 total input and output points, generally do not have so many machines, can hang these expansion modules spread out. Switching input > input point, typically 24V DC input voltage. The input voltage of different PLCs is not the same as positive or negative, and it is also different with a 24V input or an external power supply that is used with this unit.

All input and output signals are switched on and off, one of which is 0 is off. > to illustrate the input and output signals.

For example, the first input of the start signal connected to the motor, the second signal, then the stop, then the middle point of the first output relay, then the contactor, the motor controls the operation. When you press the start button, the first input lights up, the program detects a start signal input, the program executes, the first output point of the action, the intermediate relay, the contactor acts, and the motor works. The second signal input point, when the stop signal is pressed, the program operates, when the stop operation is performed, the output point is closed first, the relay is energized, the contact stops working, and the motor stops working.

Switching input module: is the processing module of external control signal or field detection signal to PLC CPU, external signals are generally buttons, proximity switches, travel switches, etc., switching output module: is the result of logic processing by PLC according to the input module input signal and internal logic cracking, and the switching output will output high and low level signals by the output module, driving external intermediate relays, contactors, indicator lights, solenoid valves and other components, and then making external equipment carry out corresponding actions.

Switching input and output module is a device that can collect switching signals into control output, usually also known as digital IO module, through the RS-485 bus the switching signal is collected to the computer or the computer sends relevant instructions to control the relevant state of the switch through the module, and can also communicate in pairs through the RS-485 bus, and remotely control the relevant state of the switch.