The industrial environment is complex and changeable, and there are various interference sources. The anti-interference ability of Industrial Data Transmission Line is crucial, and its measurement involves multiple aspects.
1. Electromagnetic Compatibility (EMC) Standard
Electromagnetic compatibility standards are an important basis for measuring the anti-interference ability of Industrial Data Transmission Line. There are a series of EMC standards both internationally and domestically, such as CISPR (International Special Committee on Radio Interference) standards and GB/T (China National Standard) related standards. These standards measure the performance of transmission lines in electromagnetic environments by stipulating electromagnetic emissions and electromagnetic sensitivity. For example, under the prescribed electromagnetic radiation test environment, the electromagnetic radiation intensity generated by the transmission line must be lower than the limit specified by the standard to avoid interference with other equipment, which reflects the electromagnetic purity of the transmission line itself. At the same time, when the transmission line is subject to external electromagnetic interference, it should be able to maintain the stability of data transmission, that is, there are certain requirements for electromagnetic sensitivity. The lower the electromagnetic sensitivity, the stronger the anti-interference ability.
2. Signal integrity indicators
Signal integrity is one of the core indicators for measuring anti-interference ability. The first is the bit error rate, which reflects the accuracy of data transmission. In the presence of interference, the lower the bit error rate, the stronger the anti-interference ability of the transmission line. For example, in an environment where there are a large number of motors, inverters and other equipment generating electromagnetic interference in industrial sites, if the transmission line transmits a large amount of data within a certain period of time, and the bit error rate can be kept at an extremely low level, it proves that its anti-interference performance is good. The second is the jitter of the signal, which refers to the instability of the signal in time. Interference may cause increased signal jitter, and if the transmission line has good anti-interference ability, it can effectively reduce jitter so that the signal can be accurately restored at the receiving end. There is also signal attenuation and distortion. Good anti-interference ability can reduce the impact of external interference on signal attenuation and distortion, and ensure signal quality.
3. Shielding effectiveness
Shielding effectiveness is an intuitive indicator for evaluating the ability of transmission lines to resist electromagnetic interference. For Industrial Data Transmission Line with a shielding layer, shielding effectiveness measures the shielding layer's ability to isolate electromagnetic interference. Shielding effectiveness is usually expressed in decibels (dB). The higher the value, the better the shielding effect. The shielding effectiveness test is generally performed by applying electromagnetic interference of different frequencies around the transmission line and then measuring the impact on the internal signal of the transmission line. For example, in a high-frequency interference environment, if the shielding effectiveness of the transmission line can reach a high decibel value, it can effectively block high-frequency electromagnetic interference from entering the transmission line, thereby ensuring the stability of data transmission.
4. Anti-noise tolerance
Anti-noise tolerance reflects the ability of the transmission line to withstand environmental noise. Noise in an industrial environment may come from the switching action of electrical equipment, electrostatic discharge, etc. The anti-noise tolerance of the transmission line can be measured by simulating these noise environments in the laboratory and observing the data transmission of the transmission line under different noise intensities. If the transmission line can still work normally in a high-noise environment, it means that it has strong anti-interference ability and a large anti-noise tolerance.
