Industrial field sensor/FCS, DCS and PLC, instrument and meter between input and output of analog signal isolation amplifier (also called analog isolation transmitter) belongs to the category of the analog signal conditioning, and can effectively protect the analog signal isolation amplifier control circuit, at all levels to eliminate or weaken environmental noise effect on the test circuit, inhibition of common ground, frequency converter, electromagnetic valve and surge pulse interference with equipment, as well as the subordinate device has a signal pressure limiting and the function of the choke, transmitter, instrumentation, frequency converter, electromagnetic valve, PLC/DCS reliable protection device, input and output and communication interface with some harsh industrial site, the control system is complex, high temperature, vibration, humidity and jamming signal, so through the input and output analog signal isolation amplifier amplification, transformation, the loop is completely isolated, and the water is one of the effective measures of anti-interference in the automation control system,

So-called bandwidth (band width) and bandwidth, is refers to in a fixed time to transfer the amount of material, that is, in the transmission pipeline can transmit data of ability, in the digital equipment, the bandwidth is usually expressed as a BPS, the transmission of digits per second, in the analog devices, bandwidth usually transfer cycles per second or Hertz (Hz), the bandwidth of the signal is refers to the signal contains the frequency range occupied by the different frequency components,

Referred to as "frequency response, frequency response on the electronics used to describe a instruments, PLC and other equipment to the differences of different frequency signal processing ability, as well as the distortion, which is a very important parameter index,


Bandwidth index test method is as follows, the input analog signal with adjustable frequency of a sine wave, the output can be stable to follow the input signal frequency range is the biggest bandwidth, industrial engineering significance signal isolation amplifier bandwidth index is what? In the application of how we understand "bandwidth"? Bandwidth indicators reflect the response speed to change the input signal isolation amplifier, the bandwidth, the greater the isolation amplifier the faster response speed of signal change; The smaller bandwidth, an isolation amplifier is insensitive to instant changes in response to an input signal, in some cases also means that the stronger ability to resist dry,

Isolation amplifier and the isolation transmitter's working principle was that the sensors, instrumentation, PLC or standard of sending and receiving signals, such as temperature, displacement, frequency, the special signal modulation by semiconductor devices such as speed, again by light or magnetic induction device to convert the isolation of transmitting, then carries on the demodulation back into accuracy and linearity of the original signal or transform it into other signals, as well as the isolated working power supply of the signals before and after processing, to ensure that the input signal, the signal output and the auxiliary power signals before and after the transformation, namely power, between three isolation, analog signal isolation amplifier and the isolation transmitter belongs to a kind of of industrial instrumentation and sensor device, its main function is to simulate the amount of isolation, amplification, transformation and transmitting, and therefore must have signal bandwidth and frequency response of the basic technical indexes,

Industrial field signal transmission interference treatment reference solution (special inverter EMC interference isolation amplifier) :
Industrial field with variable frequency control devices, high-power electromagnetic starting equipment, GPS is EMC interference sources such as high-frequency signal wireless transceiver system, need according to the characteristics of different interference sources and system control signals to analysis the interference signal processing solutions,

1, the sensor output analog signal interference on
In sensor output with ISO series analog signal isolation amplifier can effectively solve the analog signal transmission in the process of attenuation and EMC interference, enhance the stability and reliability of display control system, used in the simulation of the inverter EMC interference signal isolation amplifier: ISO EM U - P - O - M series, is mounted inside the IC input signal interference suppression filter circuit and output harmonic absorbing circuit, enhanced EMC electromagnetic interference resistance and high frequency signal interference function space, especially suitable for field with frequency conversion control equipment, high power electromagnetic starter, GPS high frequency signal wireless transceiver,

2, the high frequency signal radiation space interference
Each control system, equipment, equipped with metal shielding box (different frequency use of metal component) and the outer reliable grounding, signal communication transmission line using twisted-pair shielded cable,

3, RS232/RS485 telecommunication line interference
On the RS232/RS485 communication interface with DC - DC isolation module power supply, communication power supply and other power supply directly isolated, signal communication transmission lines also want to use twisted-pair shielded cable shielding layer (ground),

4, the system of the power supply circuit interference
Site has a large current thyristor, frequency conversion control equipment, high power electromagnetic starter, distortion influence on power system power supply parameters will, through the power circuit, the jamming signal will enter the field of each control device, therefore, must first determine the scene of various grounding device is good, the power supply of each device to add to its matching supply filter (low-pass EMI filter or inhibit reactor),

The bandwidth of the analog signal isolation amplifier isolation transmitter and frequency response industrial site technical indicators selection application reference:
1, slow analog signal in frequency (& lt; 50 hz) occasions (such as temperature, pressure, displacement, flow, etc.), can choose smaller bandwidth, low frequency sound isolation amplifier: ISO EM U (A) - P - O - M series products (M: low-frequency sound), so in the inverter control system, to curb and isolation of EMC interference, often choose: ISO EM U - P - O - M series isolation amplifier,

2, the analog signal changes in high frequency (& gt; 2 KHZ) occasions (such as measuring speed, adjust the high-speed electronic switch, switch power supply of PWM control, etc.), to ensure data integrity and reliable, often choose high bandwidth, high low frequency sound isolation amplifier: ISO EM U (A) - P - O - H series products
(H: high frequency),

3, high frequency and low frequency sound environment most system besides the choice regular frequency response (2 k) products: ISO EM A - P - O or ISO EM U - P - O series,

4, on the environment have strong magnetic space interference (high-frequency electromagnetic high current load) occasions can choose photoelectric isolation amplifier: ISO U (A) - P - O - M series,