Briefly describe the advantages and disadvantages of embedded real-time operating systems?
Develop real-time applications in an embedded real-time operating system environment, making program design and extension easy, and adding new features without major changes.However, using an embedded real-time operating system requires additional ROM/RAM overhead, 2% to 5% CPU overhead, and core cost.
What are the floor nodes?
Floor nodes include: landing doors, leveling devices (stroke switches), summoning boxes and floor controls.
What are the characteristics of the parallel modem chip interface?
Asynchronous direct SRAM interface style interface; 16-bit parallel bus data transfer; on-chip 8 KB dual-port SRAM buffer; interrupt request for data exchange.
According to the excitation method, which types of stepper motors are there?
According to the excitation method, the stepping motor can be divided into three types: reactive stepping motor, permanent magnet stepping motor and hybrid stepping motor.
Spread spectrum technology is not suitable for PLC applications, what are the advantages?
SSTs provide strong robustness in narrowband selective fading and narrowband interference environments.Both are problems in the power line channel.Due to the lower PSD, electromagnetic compatibility can also be kept in a lower range of radiation.SSTs provide multiple access features and smooth degradation in a multi-user environment.The width of the autocorrelation peak is determined by the available bandwidth and the highest waveform duration.Therefore, it is generally feasible to flexibly adapt to different needs.These reasons are primarily for ideal waveform detection and ranging tasks in wireless environments, such as in radio aircraft detection and ranging or global positioning systems.
What are the characteristics of the K-TP 178micro touch screen?
- 1.Alarm function
- 2.Variable and list functions
- 3.Screen function
- 4.Information text function
- 5.Other features
- 6.Communication between K-TP 178micro and PLC
- 7.Power supply
- 8.LED indicator
There are two types of supercapacitors, what are they?
Electric double layer capacitors and tantalum capacitors.
What is the zero temperature drift?
The zero temperature drift is caused by the inconsistency of the resistance of the four diffusion Resistorss and their temperature coefficients.
Why is the reverse non-return to zero code generally not suitable for actual transmission?
There is a DC component, and the channel is generally difficult to transmit frequency components near the zero frequency. The receiving threshold is related to the signal power and is inconvenient to use. It cannot be directly used to extract the bit synchronization signal because the NRZ does not contain the bit synchronization signal frequency component. Require a ground in the transmission line.
What are the main aspects of magnetic field biological effects?
The biological effects of magnetic fields are mainly manifested as:
- 1. Magnetic field affects the movement of electrons and ions: some biological phenomena in living organisms are related to the movement and transmission of electrons or ions.
- 2. Magnetic resonance and magnetic moment magnetic resonance can cause a variety of biomagnetic effects.
- 3. Magnetic field affects biofilm penetration and biological metabolism: an external magnetic field can change the charged ions in the biofilm exchange material, thereby affecting the penetration ability.
COMMENTS