ECPSR-086370-001 HKQCS在线零件

Description

ECPSR-086370-001 HKQCS在线零件

Al和AO的讲解
(1) AI信号:模拟量输入
所谓模拟量即4-20mA或0- 10V的电流或电压信号，输入到DCS中，经过变换，还原出原来的值，比如电流值到DCS中显示出来;电流互感器二次值(5A)经过电流变送器转换成4-20mA信号(5A对应20mA) 输入到DCS机柜,经过转换，在DCS中显示实际的电流值。
(2) AO信号:模拟量输出
和Al相反，AO是DCS输出4-20mA或0-10V信号，去控制设备的运行参数;比如，变频器的速度控制过程，以40HZ为例，通过远程DCS控制，认为给定参数值: 40HZ, DCS同样发出一个对应的模拟量电流值，在4-20mA范围内(20mA对应50HZ) ， 信号传入到变频器的控制器，变频器按照要求运行在40HZ。

模拟量概念
在了解完上面的知识后，理解模拟量首先要了解几个概念，传感器、变送器、执行器还有AD转换器、DA转换器等。

那么这里所说的传感器，我们常用的传感器有哪些呢?常用的有温度传感器，又包括了热电阻和热电偶这两种类型，还有压力传感器、湿度传感器等等。传感器是用于模拟量输入的,用于采集外部的温度、湿度、压力等信号。

温度探头一般不可以直接接 入常用模拟量模块，需要接入专用温度模块，或者加变送器。一般压力传感器也不能直接接入模拟量模块，一 般是购买自带变送器，或者使用压力变送器。
那么当传感器和变送器结合使用的时候可以将非电物理量转换成统-的标准电量。这就是传感器和变送器一个作用。

传感器和变送器转换出来的是一个标准电量，是电信号,我们的PLC是不能直接接收电信号的，那么就需要一个转换， 也就是AD转换，将模拟量转换成数字量。
在我们PLC这边，AD转换器其实就是一个模拟量的输入模块， 而DA转换器就是模拟量的输出模块。
而对于模拟量输出，我们是做模拟量控制变频器速度,从而控制电机速度;或者是模拟量控制伺服力矩和速度控制;又或者是模拟量控制比例阀的开度控制等。

ECPSR-086370-001

ECPSR-086370-001 HKQCS在线零件

Al and AO’s explanation
(1) AI signal: analog input
The so-called analog quantity is 4-20mA or 0-10V current or voltage signal, input into the DCS, after transformation, restore the original value, such as the current value displayed in the DCS; The secondary value of the current transformer (5A) is converted by the current transmitter into a 4-20mA signal (5A corresponds to 20mA) and input to the DCS cabinet. After conversion, the actual current value is displayed in the DCS.
(2) AO signal: analog output
In contrast to Al, AO is the DCS output 4-20mA or 0-10V signal to control the operating parameters of the equipment; For example, the speed control process of the frequency converter, taking 40HZ as an example, through remote DCS control, that given the parameter value: 40HZ, DCS also sends a corresponding analog current value, in the range of 4-20mA (20mA corresponds to 50HZ), the signal is passed to the controller of the frequency converter, and the frequency converter runs at 40HZ as required.

Analog concept
After understanding the above knowledge, to understand the analog first to understand several concepts, sensors, transmitters, actuators and AD converter, DA converter and so on.

So the sensors mentioned here, what are the sensors we commonly use? Commonly used temperature sensors, including thermal resistance and thermocouple these two types, as well as pressure sensors, humidity sensors and so on. The sensor is used for analog input, which is used to collect external temperature, humidity, pressure and other signals.

The temperature probe can not be directly connected to the common analog module, the need to access the special temperature module, or add a transmitter. Generally, the pressure sensor can not be directly connected to the analog module, and it is generally necessary to buy its own transmitter, or use a pressure transmitter.
Then when the sensor and the transmitter are used in combination, the non-electrical physical quantity can be converted into a standard electricity quantity. That’s where sensors and transmitters come in.

Sensor and transmitter conversion is a standard electricity, is an electrical signal, our PLC is not able to directly receive electrical signals, then you need a conversion, that is, AD conversion, the analog quantity into digital quantity.
In our PLC side, the AD converter is actually an analog input module, and the DA converter is an analog output module.
For the analog output, we do the analog control frequency converter speed, so as to control the motor speed; Or analog control servo torque and speed control; Or it is the opening control of the analog proportional valve.