Want to collect signal of imitate of of all kinds sensor successfully to PLC/DCS/FCS/MCU/FA/PC system, the function that is about to collect a system according to sensor and data and technical characteristic undertake matching type selecting, the power supply difference that also should consider the data such as industrial spot sensor and PLC collects a system at the same time and the influence that all sorts of EMC disturb, evacuation of the imitate signal segregation that outputs sensor normally, enlarge, changeover collects a system to the data such as PLC. PLC collects the imitate of sensor or digital signal through line, undertake handling next, if sensor is imitate output, PLC is about to receive imitate to input interface, if sensor is digital signal output, PLC is about to receive a number to input interface.

 

Switch quantity sensor is a switch that does not have contact, switch measures sensor to be able to measure input signal as the switch of PLC. Use at switch to measure pilot equipment commonly, machine tool, the machine. Imitate quantity sensor is a different physical quantity (like pressure, discharge, temperature) changeover is measured into imitate (the voltage) of the electric current of 4-20MA or 1-5V. Imitate quantity sensor measures the input signal that inputs module as the imitate of PLC. Use at the process to control commonly. Digital sensor is to point to will traditional imitate pattern to sensor is installed through adding or transform A/D to change module, word of made output signal amount to is measured (or the number codes) sensor, basically include: Converter of amplifier, A/D, microprocessor (CPU) , circuit of interface of memory, communication.

 

Cent is made for two lines and 4 lines make commonly used imitate quantity sensor, two lines are made and 4 lines are made have two line only, the main distinction between them depends on: Two line want two thready to perhaps change to sensor already send implement power supply, want to provide voltaic voltage signal again; And two line offer 4 thready only voltaic signal. The sensor that offers two lines to make voltaic voltage signal normally perhaps changes send implement be passive; And the sensor that offers 4 lines to make voltaic signal perhaps changes send implement be active.

 

Accordingly, the set of passageway of pattern plate input that collects a system when the data such as PLC is join when 4 lines make sensor, PLC collects imitate signal from the terminal of pattern plate passageway only, and when the pattern plate that collects a system when the data such as PLC inputs passageway set to make sensor for link second line, the imitate input of PLC outputs the power source of 24V of a dc outwards even on the passageway of pattern plate, with drive two lines make sensor work.

 

4-20mA and electrical engineering standard are concerned, 4-20mA signal is made is international Electrotechnical Committee (system of IEC) process control uses imitate signal level. Our country begins to use signal of standard of this one international to make from DDZ- Ⅲ dynamoelectric appearance, appearance transmits signal to use 4-20mA, contact signal uses 1-5VDC, use electric current to transmit namely, the signal system that voltage receives. Because signal start electric current is 4mA, send to change implement provided static job electricity, appearance is electric at the same time was 4mA at 0 o’clock, not with machinery at 0 o’clock coincide, this kind of work was helpful for identifying at 0 o’clock cut off the power and break the breakdown such as the line.

 

Industrial spot sensor and data collect a system to match applied program

 

One, match type selecting according to the function of imitate signal sensor

 

1, two lines make electricity / voltage outputs sensor (without power supply source, provide 16—24V distribution by load, output 4-20mA/0-5V) .

 

1.1 two lines make passive 4-20mA input sensor, after via electric current segregation matchs electric equipment distribution, join with PLC. If the graph is shown 1 times, call heavy, range finding sensor termination 16—24VDC, negative end exports 4-20mA electricity.

 

Graph 1 two lines make 4-20mA segregation match electric equipment representative application to pursue (ISO 4-20mA-F)

 

1.2 two lines make input of passive voltage signal sensor, via after voltage matchs electric equipment distribution, joining with PLC. If pursue 2, the graph is shown 3 times, sensor of feet of displacement, electron is being carried, voltage of negative termination 16—24VDC.
 

 

 

Graph 2 blame keep apart voltage of two lines passive to distribute electric equipment

 

Graph 3 segregation voltage distributes electric equipment

 

If pursue 4, the graph is shown 5 times, stress piece, say heavy bridge sensor is being carried, voltage of negative termination 16—24VDC.

 

Graph signal of 4 segregation voltage changes enlarge (ISO V-4-20mA)

 

Graph voltage of 5 segregation bridge distributes electric equipment (ISO V-4-20mA)

 

After 1.3 two lines make sensor output annulus of 4-20mA electric current to pass isolator to keep apart, join with PLC. If the graph is shown 6 times, pressure, flow transducer termination 9—32VDC, negative end exports 4-20mA electricity.

 

Graph 6 two lines make representative application of isolator of road of annulus of 4-20mA electric current pursue (ISO 4-20mA)

 

1.4 two lines make sensor output 4-20mA electric current to match via keeping apart recuperation (resolve the conflict between input output) hind join with PLC. If the graph is shown 7 times, sensor of temperature, rotate speed termination 12—24VDC, negative end exports 4-20mA electricity.

 

 

Graph 7 two lines make 4-20mA signal and PLC match segregation to recuperate representative application to pursue (ISO 4-20mA-P)

 

2, 4 lines make electricity / voltage (input / output) model sensor (the 24VDC of power supply source that has oneself, input / output: 4- 20mA or 0-5V) .

 

2.1 4 lines make voltaic output sensor keep apart enlarge hind and PLC join via imitate signal.

 

2.1.1 like the graph 8 are shown, sensor of temperature, humidity termination 24VDC, negative end exports 4-20mA electricity.

 

After 8 4 lines make sensor signal I/I keep apart enlarge, the graph pursues with PLC join representative application (ISO EM-A-P-O)

 

2.1.2 like the graph 9 are shown, sensor of pressure, rotate speed termination 24VDC, negative end exports 4-20mA electricity.

 

After 9 4 lines make sensor signal I/V change, the graph pursues with PLC join representative application (ISO EM-A-P-O)

 

2.2 4 lines make voltage output sensor keep apart enlarge hind and PLC join via imitate signal.

 

2.2.1 like the graph 10 are shown, sensor of pressure, rotate speed, power source of negative termination 24V, output end outputs 0-5V voltage.

 

After 10 4 lines make sensor signal V/I change, the graph pursues with PLC join representative application (ISO EM-U-P-O)

 

2.2.2 like the graph 11 are shown, fluid, flow transducer, power source of negative termination 24V, output end outputs 0-5V voltage.

 

 

After 11 4 lines make sensor signal V/V keep apart, the graph pursues with PLC join representative application (ISO EM-U-P-O)

 

2, the join of PLC and sensor matchs type selecting

 

Choice PLC (it is with 2# connect, 3# connect is negative citing)

 

1, the anode when two lines are made voltage of 2 output 24vdc, 3 receive electricity, when encountering two lines to make sensor so, one kind receives a standard is 2 receive sensor, 3 receive sensor to lose; Jump the line makes voltaic signal for two lines. 2 kinds receive a standard is 2 impending, 3 those who receive sensor is negative, at the same time sensor is receiving the 24vdc inside ark; Jump the line makes voltaic signal for two lines. (with 2, 3 lose for exemple)

 

2, the anode when 4 lines are made 2 it is to receive electricity, 3 it is negative pole. (4 lines make profit is the M inside signal of sensor negative pole and ark precision won’t be affected when be different n very big, because be the loop of sensor itself electric current) when encountering 4 lines to make sensor, a kind of method is 2 receive sensor, 3 receive sensor to lose, plc jumps the line makes electricity for 4 lines. (with 2, 3 lose for exemple)

 

3, 4 lines make two lines of sensor and PLC jump the line receives a standard: Line is lost be linked together with line of the M inside ark. sensor with PLC 3 be linked together, 2 impending, jump the line makes electricity for two lines. (with 2, 3 lose for exemple)

 

4, voltage signal: 2 receive sensor, 3 receive sensor to lose, PLC jumps the line is voltage signal. (with 2, 3 lose for exemple)