Several common output signals of pressure sensors
The output signals commonly used by sensors can be divided into three types. Each different signal output is an incremental code signal, an absolute code signal, and a switch signal. These three signals have their own advantages and disadvantages. Next, through a simple overview, let everyone have a certain understanding of their characteristics.
Sensor output signal
Analog signal: refers to a continuous signal in the given range of information parameters. Or during a continuous time interval, the characteristic quantity of the representative information may be present as an arbitrary value signal at any moment, and the amplitude, or frequency, or phase of the signal continuously changes with time, such as a currently broadcasted sound signal, or Image signal and so on.
Digital signal: The amplitude value is discrete, and the amplitude value is limited to a limited number of values. Binary code is a digital signal. Binary codes are affected by noise and are easily processed by digital circuits, so they have been widely used.
We usually divide sensor signals into analog and digital signals. But besides some simple classifications, knowing other classifications is still very helpful to us.
Incremental code signal: means that the measured value is proportional to the number of change cycles of the sensor output signal, that is, the magnitude of the output value is determined by the increment of the number of signal change cycles. When a grating displacement sensor, a magnetic grating displacement sensor, a laser displacement sensor, or the like measures displacement using an interference method or the like, the signal output by the sensor is an incremental code signal.
Absolute code signal: A signal that corresponds to the state of the measured object. Like a code wheel, each of its angular positions corresponds to a set of codes, which are called absolute codes. Absolute code signals have strong anti-jamming capability. Regardless of what happens during the measurement process, after a disturbance, a state always corresponds to a defined set of codes.
Switching signal: The switching signal has only two states, 0 and 1. It can be regarded as a special case where the absolute code has only one bit. The output of a sensor such as a trip switch and a photoelectric switch is a switch signal.