Special isolation for plcdcs analog interface of t

Shunyuan isolation amplifier special isolation transmitter for plc/dcs analog interface

in the industrial field, various analog sensors such as pressure, displacement, temperature, flow and speed are designed with different technical methods. The working power distribution mode of the sensor is mainly divided into two-wire system and four wire system, and the output analog signals are also different, while the common ones are ma/ma current signal and mv/v/v voltage signal. To successfully collect all kinds of sensor analog signals into the plc/dcs/fcs/mcu/fa/pc system, it is necessary to match and select the type according to the functions and technical characteristics of the sensor and the data acquisition system. At the same time, it is also necessary to consider the power supply difference between the industrial field sensor and the PLC and other data acquisition systems and the influence of various EMC interference. Generally, the analog signals output by the sensor are isolated, amplified and converted and then sent to the PLC and other data acquisition systems. PLC collects the analog or digital signals of the sensor through the signal line, and then processes them. If the sensor is analog output, PLC should connect to the analog input interface. If the sensor is digital signal output, PLC should connect to the digital input interface

the switching value sensor is a contactless switch, which can be used as the switching value input signal of PLC. Generally used for switching value control equipment, machine tools, machines, etc. Analog quantity sensor converts different physical quantities (such as pressure, flow, temperature) into analog quantities (MA current or V voltage). The analog sensor is used as the input signal of the analog input module of PLC. Generally used for process control. Tensile testing machine is a multi-functional tensile machine digital sensor, which refers to the sensor that adds or modifies the traditional analog sensor with a/d conversion module to make its output signal digital (or digital coding), mainly including amplifier, a/d converter, microprocessor (CPU), memory, communication interface circuit, etc

commonly used analog sensors are divided into two-wire system and four wire system. Both two-wire system and four wire system have only two signal lines. The main difference between them is that the two signal lines of two-wire system not only supply power to the sensor or transmitter, but also provide current and voltage signals; The two four wire signal lines only provide current signals. Therefore, the sensors or transmitters that provide two-wire current and voltage signals are usually passive; The sensor or transmitter that provides four wire current signal is active. Therefore, when the template input channel of data acquisition systems such as PLC is set to connect four wire sensors, PLC only collects analog signals from the terminals of the template channel, while when the template input channel of data acquisition systems such as PLC is set to connect two-wire sensors, the analog input channel of PLC will also output a 24V DC power supply to drive the two-wire sensors

ma is related to the electrical standard. The Ma signal system is the analog signal standard used by the International Electrotechnical Commission (IEC) process control system. China has adopted this international standard signal system since ddz- Ⅲ electric instrument. The instrument transmission signal adopts Ma, and the contact signal adopts VDC, that is, the signal system of current transmission and voltage reception. Because the starting current of the signal is 4mA, it provides static working current for the transmitter, and the electrical zero point of the instrument is 4mA, which does not coincide with the mechanical zero point. This active zero point is conducive to identifying faults such as power failure and disconnection

in the industrial field, various analog sensors such as pressure, displacement, temperature, flow and speed are designed with different technical methods. The working power distribution mode of the sensor is mainly divided into two-wire system and four wire system, and the output analog signals are also different, while the common ones are ma/ma current signal and mv/v/v voltage signal. To successfully collect all kinds of sensor analog signals into the plc/dcs/fcs/mcu/fa/pc system, it is necessary to match and select the type according to the functions and technical characteristics of the sensor and the data acquisition system. At the same time, it is also necessary to consider the power supply difference between the industrial field sensor and the PLC and other data acquisition systems and the influence of various EMC interference. Generally, the analog signals output by the sensor are isolated, amplified and converted and then sent to the PLC and other data acquisition systems. PLC collects the analog or digital signals of the sensor through the signal line, and then processes them. If the sensor is analog output, PLC should connect to the analog input interface. If the sensor is digital signal output, PLC should connect to the digital input interface

the switching value sensor is a contactless switch, which can be used as the switching value input signal of PLC. Generally used for switching value control equipment, machine tools, machines, etc. Analog quantity sensor converts different physical quantities (such as pressure, flow, temperature) into analog quantities (MA current or V voltage). The analog sensor is used as the input signal of the analog input module of PLC. Generally used for process control. Digital sensor refers to the sensor that adds or modifies the a/d conversion module of the traditional analog sensor to make its output signal digital (or digital coding), mainly including amplifier, a/d converter, microprocessor (CPU), memory, communication interface circuit, etc

commonly used analog sensors are divided into two-wire system and four wire system. Both two-wire system and four wire system have only two signal lines. The main difference between them is that the two signal lines of two-wire system not only supply power to the sensor or transmitter, but also provide current and voltage signals; The two four wire signal lines only provide current signals. Therefore, the sensors or transmitters that provide two-wire current and voltage signals are usually passive; The sensor or transmitter that provides four wire current signal is active. Therefore, when the template input channel of data acquisition systems such as PLC is set to connect four wire sensors, PLC only collects analog signals from the terminals of the template channel, while when the template input channel of data acquisition systems such as PLC is set to connect two-wire sensors, the analog input channel of PLC will also output a 24V DC power supply to drive the two-wire sensors

ma is related to the electrical standard. The Ma signal system is the analog signal standard used by the International Electrotechnical Commission (IEC) process control system. China has adopted this international standard signal system since ddz- Ⅲ electric instruments. The instrument transmission signal adopts Ma and the contact signal adopts VDC, that is, the signal system of current transmission and voltage reception is adopted. Because the starting current of the signal is 4mA, it provides static working current for the transmitter, and the electrical zero point of the instrument is 4mA, which does not coincide with the mechanical zero point. This active zero point is conducive to identifying faults such as power failure and disconnection

industrial field PLC, DCS upper computer and lower computer signal acquisition, isolation and conversion low-cost small volume supporting scheme

one and two-wire passive current signal isolator: din3 ISO Ma

iso Ma is a transmitter that outputs the current signal (ma/ma/MA) in proportion after isolating the sensor signal (ma/ma/ma). The product includes input signal interference suppression filter circuit, signal modulation circuit, signal isolation circuit and output demodulation filter circuit. Wide creepage distance at input and output sides and internal isolation measures enable this series of products to achieve an isolation voltage of 3kVac between signal input and signal output

din3 ISO Ma products can be used in the following three conversions:

1, Ma signal input and isolated Ma signal output

2. Ma signal input, isolate Ma signal output

3. Ma signal input, isolate Ma signal output

two wire passive voltage signal isolation distributor: din3 ISO v-ma

iso v-ma is a two-wire voltage signal isolation distribution module, which can realize the voltage signal distribution of two-wire voltage input distribution sensor and Bridge (weighing) detection circuit. It contains current signal modulation circuit, electromagnetic isolation conversion circuit and signal reduction demodulation circuit. The power supply voltage range is VDC, the input equivalent resistance is small, the linearity is high, and the isolation and withstand voltage between the signal input and output can reach 2500vac. The product is very convenient to use. Customers only need to add a few peripheral devices to the front of the product to realize the voltage signal isolation output function of the two-wire voltage input distribution sensor and the bridge (weighing) detection circuit

three and two-wire passive current signal isolation distributor: din3 ISO ma-f

iso ma-f is a two-wire Ma signal loop isolation distributor, which has the functions of energy saving, safety and explosion-proof. The distributor can distribute 16v~21.5v for two-wire sensors, which facilitates the power supply, signal measurement, remote transmission and other functions of some two-wire passive sensors. The output of the distributor is designed for the two-wire power supply circuit (on-site explosion-proof function) with 24VDC and sampling resistance (load resistance) in series. It matches with the analog input and output interface board (upper computer, lower computer), PLC, DCS or other analog input and output control ports of data acquisition equipment commonly used on site. When ISO ma-f products are used, The power supply and signal on the external sensor at the input end are coupled from the output end by the Ma distributor module. This electrical signal can be controlled by PLC, DCS and industrial control computer. When it is necessary to collect data, the sensor can be powered on, and when it is not necessary, the power supply and signal can be turned off, so as to realize the functions of energy saving and explosion-proof, which can realize on-site multi-point data acquisition and control, and also extend the service life of the sensor

din3 ISO ma-f products can be used in the following three conversions:

1, Ma signal input, isolated distribution Ma signal output

2. Ma signal input, isolated distribution Ma signal output

3. Ma signal input, isolated distribution Ma signal output

four and two-wire current signal isolation conditioner: din3 ISO ma-p

ISO ma-p is a two-wire Ma signal isolation conditioner, which is mainly used to solve the signal interference and conflict between plc/dcs control system and sensors, upper computer, lower computer and other data acquisition, actuator. Its principle is to use a linear optocoupler to isolate the input and output circuits of the signal, and control the linear transmission accuracy and linearity of the analog signal through the comparison, adjustment, feedback and amplification circuit. There is no need for separate power supply, and the two-wire distribution circuit output mode is adopted. The IC contains current signal modulation and demodulation circuit, signal coupling isolation and conversion circuit, etc. A small input equivalent resistance, such as the 5000 ton range of Beijing kangdexin, will be increased by 2000 to 7000 tons by the end of this year, so that the signal voltage collected by the IC from the sensor circuit can reach an ultra wide range (7.5 32V), so as to meet the needs of users to realize long-distance and distortion free signal transmission without external auxiliary power supply. The IC output is designed for the two-wire power supply circuit with 24VDC and sampling resistance (or load resistance) in series, and matches with the analog input and output interface board (upper computer, lower computer), PLC, DCS or other analog input and output control ports of data acquisition equipment commonly used on site. The product is very convenient to use. Just connect a 50K multi turn potentiometer externally for adj correction to realize the isolation, transmission and transmission functions of two-wire Ma signal

v. 0- 10v/0- 20mA bidirectional DC (voltage/current) signal isolation amplifier transmitter: din3 ISO EM Series

iso EM u-p-o and ISO EM a-p-o series isolation amplifiers are a hybrid integrated circuit with magnetoelectric isolation. This IC integrates a multi isolated dc/dc conversion power supply and a group of magnetoelectric coupled analog signal isolation amplifiers on the same chip, which adopts the low-cost scheme of magnetoelectric coupling, It is mainly used in occasions without special requirements for EMC (electromagnetic interference). Wide creepage distance at input and output sides and internal isolation measures enable the chip to