CN212726989U

CN212726989U - Communication RS232 signal isolation explosion-proof safety barrier

Info

Publication number: CN212726989U
Application number: CN202022066808.3U
Authority: CN
Inventors: 李威; 周虎; 侯荣奇
Original assignee: Suzhou Beijiafu Electric Automation Co ltd
Current assignee: Suzhou Beijiafu Electric Automation Co ltd
Priority date: 2020-09-09
Filing date: 2020-09-09
Publication date: 2021-03-16
Anticipated expiration: 2030-09-09

Abstract

An RS232 bus communication is carried out between a host controller and a field sensor and an actuator, field data acquisition or detection and control of a downlink control instruction are carried out, data transmission, automatic control and remote operation are carried out, meanwhile, explosion-proof treatment is carried out, energy on a data line during communication of RS232 equipment is limited, explosive mixtures cannot be ignited, meanwhile, electrical isolation is carried out on the two equipment, and anti-interference performance of an industrial control network is enhanced. The invention can enable any control detection equipment with the RS232 interface to carry out data transmission between the safety area and the dangerous area, and can realize the function of electrical isolation. The RS232 interface of the intrinsic safety end can be provided for equipment in a dangerous area, and the production operation safety in the flammable and explosive environment is protected. The safety barrier and the dangerous area are separated, the energy on the transmission line is limited in a safe range, and the safety barrier is very convenient and practical.

Description

Communication RS232 signal isolation explosion-proof safety barrier

Technical Field

The invention relates to a signal isolation safety device, in particular to a communication RS232 signal isolation explosion-proof safety barrier which is used for performing RS232 bus communication between a host controller and a field sensor and an actuator, performing field data acquisition or detection and control of a downlink control instruction, performing data transmission, automatic control and remote operation, and performing data isolation transmission and explosion-proof treatment.

Background

With the continuous improvement of the industrial automation degree, the application of automatic control is higher and higher, and the communication between the field sensor and the controller is indispensable. RS232 is one of communication interfaces on computers, and is an asynchronous transmission standard interface established by the institute of electronics and industry, and is widely used in microcomputer communication interfaces at present. However, the common RS232 data line cannot be directly used in the places with explosive dangers, such as coal, petrochemical industry, natural gas and the like, and when RS232 communication is carried out in these fields, the danger that the line is ignited to ignite the explosive combustible materials exists.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a communication RS232 signal isolation explosion-proof safety barrier which is used for performing RS232 bus communication between a host controller and a field sensor and an actuator, performing field data acquisition or detection and control of a downlink control instruction, performing data transmission, automatic control and remote operation, and performing data isolation transmission and explosion-proof treatment.

The technical scheme adopted by the invention for solving the technical problems is as follows: the utility model provides an explosion-proof safety barrier of communication RS232 signal isolation, including this ampere of end RS232 conversion chip U1 and non-this ampere of end RS232 conversion chip U2 and input terminal U3A and output terminal U3C, input terminal U3A signals are to this ampere of end RS232 conversion chip U1 of carrying, this ampere of end RS232 conversion chip U1 control the input of transmission opto-coupler U4 and the output of receiving opto-coupler U5, non-this ampere of end RS232 conversion chip U2 control the input of transmission opto-coupler U4 output and receiving opto-coupler U5, non-this ampere of end RS232 conversion chip U2 output signal is to output terminal U3C, non-this ampere of end RS232 conversion chip U2 control power state pilot lamp D17, send state pilot lamp D2 and receive state pilot lamp D1.

The RS232 isolation circuit has the advantages that the RS232 isolation circuit is simultaneously subjected to explosion-proof treatment, energy on a data line during communication of RS232 equipment is limited, so that an explosive mixture cannot be ignited, the two equipment are electrically isolated, and the anti-interference performance of an industrial control network is enhanced. For example, a natural gas pipeline flowmeter with an RS232 communication function can realize reliable communication guarantee by adding the invention when a non-explosion-proof flow control instrument is electrically connected. When the communication RS232 signal isolation explosion-proof safety barrier is used for equipment communication, energy on a data line is not enough to ignite explosive mixtures during all equipment communication, and meanwhile, two pieces of equipment are electrically isolated, so that the anti-interference performance of an industrial control network is enhanced.

Drawings

The structure and characteristics of the communication RS232 signal isolation explosion-proof safety barrier of the invention are further described in the following with reference to the accompanying drawings and embodiments, wherein:

fig. 1 is a circuit diagram of a first embodiment of the present invention.

Fig. 2 is a block circuit schematic diagram of a first embodiment of the present invention.

In the figure: u1. this ampere of end RS232 conversion chip, U2. non-this ampere of end RS232 conversion chip, U3A. input terminal, U3℃ output terminal, U4. transmission opto-coupler, U5. receipt opto-coupler, D17. power status indicator, D2 sends the status indicator, D1 receives the status indicator.

Detailed Description

In the embodiment shown in fig. 1, an intrinsically safe terminal RS232 conversion chip (U1), a non intrinsically safe terminal RS232 conversion chip (U2), an input terminal (U3A), an output terminal (U3C), an emission optocoupler (U4), a receiving optocoupler (U5), a power state indicator lamp (D17), a sending state indicator lamp (D2), and a receiving state indicator lamp (D1) are provided.

In the embodiment shown in fig. 2, the circuit principle of the present invention is labeled as follows: signals are input into the explosion-proof processing circuit through a dangerous side 232 bus, the signals are input into the 232 level to TTL level conversion circuit after explosion-proof processing, then the signals are isolated through the optical coupler, safe signals are input into the TTL level to 232 level conversion, and finally the safe signals are output through a safe side 232 bus.

The communication RS232 signal isolation explosion-proof safety barrier comprises an intrinsic safety end RS232 conversion chip (U1), a non-intrinsic safety end RS232 conversion chip (U2), an input terminal (U3A) and an output terminal (U3C), wherein the input terminal (U3A) transmits signals to the intrinsic safety end RS232 conversion chip (U1), the intrinsic safety end RS232 conversion chip (U1) controls the input end of a transmitting optocoupler (U4) and the output end of a receiving optocoupler (U5), the non-intrinsic safety end RS232 conversion chip (U2) controls the output end of the transmitting optocoupler (U4) and the input end of the receiving optocoupler (U5), the non-intrinsic safety end RS232 conversion chip (U2) outputs signals to the output terminal (U3C), and the non-intrinsic safety end RS232 conversion chip (U2) controls a power state indicator lamp (D17), a transmitting state indicator lamp (D2) and a receiving state indicator lamp (D1).

According to the communication RS232 signal isolation explosion-proof safety grid, a 13 pin R1IN of an intrinsically safe end RS232 conversion chip (U1) is electrically connected with a fuse F1, the other pin of the fuse F1 is electrically connected with a resistor R6, the other end of a resistor R6 is electrically connected with a resistor R5 and the cathode ends of Zener diodes D3 and D4, the anode ends of the Zener diodes D3 and D3 are electrically connected with the anode ends of the Zener diodes D3 and D3 in parallel, the cathode ends of the Zener diodes D3 and D3 are electrically connected with the cathode (Gi) of an intrinsically safe end power supply, the other end of the resistor R3 is electrically connected with the 2 pin of an input terminal (U3 3), the 14 pin T1OUT of the intrinsically safe end RS232 conversion chip (U3) is electrically connected with the fuse F3, the other pin of the fuse F3 is electrically connected with the resistor R3, the other pin of the resistor R3 is electrically connected with the resistor R3 and the anode end of the Zener diode D3 and the D3, the anode end of the Zener diode D3 is electrically connected with the Zener diode D36, The negative terminal of the D10 is electrically connected with the negative electrode (Gi) of the intrinsic safety power supply, the other pin of the resistor (R11) is electrically connected with the pin 1 of the input terminal (U3A), and the pin 3 of the input terminal (U3A) is electrically connected with the negative electrode (Gi) of the intrinsic safety power supply.

The communication RS232 signal isolation explosion-proof safety barrier is implemented, a 12 th pin R1OUT of an intrinsically safe terminal RS232 conversion chip (U1) is electrically connected with a resistor R7, the other end of the resistor R7 is electrically connected with a base electrode of a triode Q5, an emitter electrode of a triode Q5 is electrically connected with a cathode (Gi) of an intrinsically safe terminal power supply, a collector electrode of a triode Q5 is electrically connected with a 3 rd pin of a transmitting optocoupler (U4), a 2 nd pin of the transmitting optocoupler (U4) is electrically connected with a resistor (R4), the other pin of an electric group (R4) is electrically connected with an anode (Vi) of the intrinsically safe terminal power supply, a 11 th pin T1IN of the intrinsically safe terminal RS232 conversion chip (U1) is electrically connected with one end of a resistor R9 and a 6 th pin of a receiving optocoupler (U5), the other end of a resistor R9 is electrically connected with an anode (Vi) of the intrinsically safe terminal power supply, an 8 th pin of a receiving optocoupler (U638) is electrically connected with a resistor R8, the other end of the resistor R8 is electrically connected with an anode (, the 6 th pin V-of the RS232 conversion chip (U1) of the local safety terminal is electrically connected with a capacitor C5, the other end of the capacitor C5 is electrically connected with the negative pole (Gi) of the power supply of the local safety terminal, the 2 nd pin V + of the RS232 conversion chip (U1) of the local safety terminal is electrically connected with a capacitor C6, the other end of the capacitor C6 is electrically connected with the positive pole (Vi) of the power supply of the local safety terminal, the 5 th pin C2+ of the RS232 conversion chip (U1) of the local safety terminal is electrically connected with a capacitor C1, the other end of the capacitor C1 is electrically connected with the 4 th pin C2 of the RS232 conversion chip (U1) of the local safety terminal, the 3 rd pin C1-of the RS232 conversion chip (U1) of the local safety terminal is electrically connected with a capacitor C2, the other end of the capacitor C2 is electrically connected with the 1 st pin C1+ of the RS232 conversion chip (U1) of the local safety terminal, the 16 th pin of the RS232 conversion chip (U68642) of the local safety terminal is, the 15 th pin GND of the RS232 conversion chip (U1) of the intrinsic safety terminal is electrically connected with the negative electrode (Gi) of the power supply of the intrinsic safety terminal.

According to the communication RS232 signal isolation explosion-proof safety barrier, the 11 th pin T1IN of a non-intrinsic safety end RS232 conversion chip (U2) is electrically connected with one end of a resistor R3 and the 6 th pin of an emission optocoupler (U4), the other end of the resistor R3 is electrically connected with a non-intrinsic safety end power anode (Vo), the 5 th pin of the emission optocoupler (U4) is electrically connected with a non-intrinsic safety end power cathode (Go), the 8 th pin of the emission optocoupler (U4) is electrically connected with a resistor R2, the other end of the resistor R2 is electrically connected with a non-intrinsic safety end power anode (Vo), the 12 th pin R1OUT of the non-intrinsic safety end RS232 conversion chip (U2) is electrically connected with a resistor R13, the other end of the resistor R48 is electrically connected with the base of a triode Q8, the emitter of the triode Q8 is electrically connected with a non-intrinsic safety end power cathode (Go), the collector of a triode Q2 is electrically connected with the 3 rd pin of a receiving optocoupler (U638), and the other end of the non-intrinsic safety end optocoupler (U5) is electrically connected with a non-intrinsic safety.

In the communication RS232 signal isolation explosion-proof safety grid, a 6 th pin V-of a non-intrinsic safety end RS232 conversion chip (U2) is electrically connected with a capacitor (C11), the other end of the capacitor (C11) is electrically connected with a negative electrode (Go) of a non-intrinsic safety end power supply, a 2 nd pin V + of the non-intrinsic safety end RS232 conversion chip (U2) is electrically connected with a capacitor C12, the other end of the capacitor C12 is electrically connected with a positive electrode (Vo) of the non-intrinsic safety end power supply, a 5 th pin C2-of the non-intrinsic safety end RS232 conversion chip (U2) is electrically connected with a capacitor C3, the other end of the capacitor C3 is electrically connected with a 4 th pin C2+ of the non-intrinsic safety end RS232 conversion chip (U2), a 3 rd pin C1-an electrically connected capacitor C4 of the non-intrinsic safety end RS232 conversion chip (U2), the other end C4 is electrically connected with a 1 st pin C1+ of the non-intrinsic safety end RS232 conversion chip (U73727) and a positive electrode (VCC 3616) of the non-intrinsic safety end RS 14, the other end of the capacitor C14 is electrically connected with a negative pole (Go) of a non-intrinsic safety end power supply, a positive pole (Vo) of the non-intrinsic safety end power supply is electrically connected with a positive pole end of the sending state indicating lamp (D2), a negative pole end of the sending state indicating lamp (D2) is electrically connected with a resistor R25, the other end of the resistor R25 is electrically connected with an emitter of a triode Q3, a base of a triode Q3 is electrically connected with a resistor R14, the other end of a resistor R14 is electrically connected with a (TX) end of a pin T1IN of the RS232 conversion chip (U2) of the non-intrinsic safety end, a collector of the triode Q3 is electrically connected with a negative pole (Go) of the non-intrinsic safety end power supply, a positive pole (Vo) of the receiving state indicating lamp (D1) is electrically connected with a negative pole end of the resistor R26, the other end of the resistor R26 is electrically connected with an emitter of the triode Q4, a base of the triode Q4 is electrically connected with a resistor R27, the other end of the resistor, non-intrinsic safety end power negative pole (Go) is connected to triode Q4 collecting electrode electricity, non-intrinsic safety end power positive pole (Vo) electricity connecting resistance (R39), resistance (R39) other end electricity connection power status indicator lamp (D17) positive terminal, power status indicator lamp (D17) negative terminal electricity connecting intrinsic safety end power negative pole (Go), non-intrinsic safety end power positive pole (Vo) and electric capacity C14 are connected to 16 th foot VCC of non-intrinsic safety end RS232 conversion chip (U2) electricity, non-intrinsic safety end power negative pole (Go) is connected to electric capacity C14's the other end electricity, non-intrinsic safety end power negative pole (Go) is connected to non-intrinsic safety end RS232 conversion chip (U2)'s 15 th foot GND electricity.

According to the communication RS232 signal isolation explosion-proof safety barrier, 13 pins R1IN of a non-intrinsic safety end RS232 conversion chip (U2) are electrically connected with a resistor R16, the other end of the resistor R16 is electrically connected with 7 pins of an output terminal (U3C), 14 pins T1OUT of the non-intrinsic safety end RS232 conversion chip (U2) are electrically connected with a resistor R15, the other end of the resistor R15 is electrically connected with 8 pins of the output terminal (U3C), and 9 pins of the output terminal (U3C) are electrically connected with a negative electrode (Go) of a non-intrinsic safety end power supply.

The communication RS232 signal isolation explosion-proof safety barrier can overcome the defects of the prior art, provides an RS232 isolation circuit, simultaneously performs explosion-proof treatment, can relate to the situation that the energy on a data line is not enough to ignite an explosive mixture during the communication of any RS232 equipment, and simultaneously electrically isolates the two equipment, thereby enhancing the anti-interference performance of an industrial control network.

The communication RS232 signal isolation explosion-proof safety barrier can provide an RS232 isolation circuit, simultaneously carries out explosion-proof treatment, limits the energy on a data line during communication of RS232 equipment, enables the energy to be insufficient for igniting explosive mixtures, simultaneously electrically isolates the two equipment, and enhances the anti-interference performance of an industrial control network. For example: the invention provides a natural gas pipeline flowmeter with an RS232 communication function, which can realize reliable communication guarantee by being added when a non-explosion-proof flow control instrument is electrically connected.

The invention can enable any control detection equipment with the RS232 interface to carry out data transmission between the safety area and the dangerous area, and can realize the function of electrical isolation. The RS232 interface of the intrinsic safety end can be provided for equipment in a dangerous area, and the production operation safety in the flammable and explosive environment is protected. The safety barrier and the dangerous area are separated, the energy on the transmission line is limited in a safe range, and the safety barrier is very convenient and practical.

The invention has good effect.

Claims

1. The utility model provides an explosion-proof safety barrier of communication RS232 signal isolation, including this ampere of end RS232 conversion chip (U1) and non-this ampere of end RS232 conversion chip (U2) and input terminal (U3A) and output terminal (U3C), characterized in that, input terminal (U3A) carry the signal to this ampere of end RS232 conversion chip (U1), this ampere of end RS232 conversion chip (U1) control the input of transmission opto-coupler (U4) and the output of receiving opto-coupler (U5), non-this ampere of end RS232 conversion chip (U2) control transmission opto-coupler (U4) output and the input of receiving opto-coupler (U5), non-this ampere of end RS232 conversion chip (U2) output signal to output terminal (U3C), non-this ampere of end RS232 conversion chip (U2) control power status indicator lamp (D17), send status indicator lamp (D2) and receive status indicator lamp (D1).

2. The communication RS232 signal isolation explosion-proof safety grid according to claim 1, wherein a pin R1IN of the intrinsic safety terminal RS232 conversion chip (U1) is electrically connected with a fuse F1, the other pin of the fuse F1 is electrically connected with a resistor R6, the other end of the resistor R6 is electrically connected with a resistor R5 and the cathode ends of Zener diodes D3 and D4, the anode ends of Zener diodes D3 and D4 are electrically connected with the anode ends of Zener diodes D5 and D8 in parallel, the cathode ends of Zener diodes D8 and D8 are electrically connected with the anode (Gi) of the intrinsic safety terminal RS 8, the other end of the resistor R8 is electrically connected with a pin 2 of the input terminal (U3 8), a pin T10 8 of the intrinsic safety terminal RS232 conversion chip (U8) is electrically connected with a fuse F8, the other pin of the fuse F8 is electrically connected with a resistor R8, the other pin of the resistor R8 is electrically connected with a diode D8 and the anode ends of the Zener diodes D8 and D8 are electrically connected with the anode ends of the Zener diodes D8 in, The positive terminal of D10, the negative terminals of Zener diodes D9 and D10 are electrically connected with the negative terminal (Gi) of the intrinsic safety end power supply, the other pin of the resistor R11 is electrically connected with the 1 pin of the input terminal (U3A), and the 3 pin of the input terminal (U3A) is electrically connected with the negative terminal (Gi) of the intrinsic safety end power supply.

3. The communication RS232 signal isolation explosion-proof safety barrier as claimed in claim 1, wherein the 12 th pin R10UT of the RS232 conversion chip (U1) is electrically connected with the resistor R7, the other end of the resistor R7 is electrically connected with the base of the transistor Q5, the emitter of the transistor Q5 is electrically connected with the cathode (Gi) of the intrinsic safety end power supply, the collector of the transistor Q5 is electrically connected with the 3 rd pin of the emitting optocoupler (U4), the 2 nd pin (R4) of the emitting optocoupler (U4), the other pin of the electric group (R4) is electrically connected with the anode (Vi) of the intrinsic safety end power supply, the 11 th pin T1IN of the RS232 conversion chip (U1) is electrically connected with one end of the resistor R9 and the 6 th pin of the receiving optocoupler (U5), the other end of the resistor R9 is electrically connected with the anode (Vi) of the intrinsic safety end power supply, the 8 th pin of the receiving optocoupler (U5) is electrically connected with the anode (Vi) of the resistor R8), the 5 th pin of the receiving optocoupler (U5) is electrically connected with the intrinsic safety end power supply cathode (Gi), the 6 th pin V-of the intrinsic safety end RS232 conversion chip (U1) is electrically connected with the capacitor C5, the other end of the capacitor C5 is electrically connected with the intrinsic safety end power supply cathode (Gi), the 2 nd pin V + of the intrinsic safety end RS232 conversion chip (U1) is electrically connected with the capacitor C6, the other end of the capacitor C6 is electrically connected with the intrinsic safety end power supply anode (Vi), the 5 th pin C2+ of the intrinsic safety end RS232 conversion chip (U1) is electrically connected with the capacitor C1, the other end of the capacitor C1 is electrically connected with the 4 th pin C8 of the intrinsic safety end RS232 conversion chip (U1), the intrinsic safety end RS232 conversion chip (U1) is electrically connected with the capacitor C1-C2, the other end of the capacitor C2 is electrically connected with the 1 st pin C42 + of the intrinsic safety end RS232 conversion chip (U1), the intrinsic safety end RS232 conversion chip (VCC 4616) and the intrinsic safety end C13, the other end of the capacitor C13 is electrically connected with the power supply cathode (Gi) of the intrinsic safety terminal, and the 15 th pin GND of the RS232 conversion chip (U1) of the intrinsic safety terminal is electrically connected with the power supply cathode (Gi) of the intrinsic safety terminal.

4. The communication RS232 signal isolation explosion-proof safety barrier as claimed in claim 1, wherein the 11 th pin T1IN of the non-intrinsic safety terminal RS232 conversion chip (U2) is electrically connected with one end of the resistor R3 and the 6 th pin of the transmitting optocoupler (U4), the other end of the resistor R3 is electrically connected with the positive electrode (Vo) of the non-intrinsic safety terminal power supply, the 5 th pin of the transmitting optocoupler (U4) is electrically connected with the negative electrode (Go) of the non-intrinsic safety terminal power supply, the 8 th pin of the transmitting optocoupler (U4) is electrically connected with the resistor R2, the other end of the resistor R2 is electrically connected with the positive electrode (Vo) of the non-intrinsic safety terminal power supply, the 12 th pin R10UT of the non-intrinsic safety terminal RS232 conversion chip (U2) is electrically connected with the resistor R48, the other end of the resistor R13 is electrically connected with the base of the triode Q8, the transmitter of the triode Q8 is electrically connected with the negative electrode (Go), the collector of the triode Q8 is electrically connected with the third pin 3 of the receiving optocoupler (U5), the other end of the resistor R10 is electrically connected with the non-intrinsic-safety end power supply positive electrode (Vo).

5. The communication RS232 signal isolation explosion-proof safety barrier as claimed in claim 1, wherein the 6 th pin V-of the non-intrinsic safety terminal RS232 conversion chip (U2) is electrically connected with the capacitor (C11), the other end of the capacitor (C11) is electrically connected with the negative electrode (Go) of the non-intrinsic safety terminal RS232 power supply, the 2 nd pin V + of the non-intrinsic safety terminal RS232 conversion chip (U2) is electrically connected with the capacitor C12, the other end of the capacitor C12 is electrically connected with the positive electrode (Vo) of the non-intrinsic safety terminal RS power supply, the 5 th pin C2-of the non-intrinsic safety terminal RS232 conversion chip (U2) is electrically connected with the capacitor C3, the other end of the capacitor C3 is electrically connected with the 4 th pin C2+ of the non-intrinsic safety terminal RS232 conversion chip (U2), the 3 rd pin C1-of the non-intrinsic safety terminal RS232 conversion chip (U2) is electrically connected with the capacitor C4, the other end of the capacitor C4 is electrically connected with the positive electrode (VCC 1) of the non-intrinsic safety terminal RS232 conversion chip (U3527) and the non-intrinsic safety terminal RS 2), the other end of the capacitor C14 is electrically connected with a negative electrode (Go) of a non-intrinsic safety end power supply, a positive electrode (Vo) of the non-intrinsic safety end power supply is electrically connected with a positive electrode end of a sending state indicator lamp (D2), a negative electrode end of the sending state indicator lamp (D2) is electrically connected with a resistor R25, the other end of the resistor R25 is electrically connected with an emitter of a triode Q3, a base electrode of the triode Q3 is electrically connected with a resistor R14, the other end of the resistor R14 is electrically connected with a (TX) end of a pin T1IN of the RS232 conversion chip (U2)11, a collector electrode of the triode Q59642 is electrically connected with a negative electrode (Go) of the non-intrinsic safety end power supply, a positive electrode end of the receiving state indicator lamp (D6327) is electrically connected with a positive electrode (Vo), a negative electrode end of the receiving state indicator lamp (D1) is electrically connected with a resistor R26, the other end of the resistor R26 is electrically connected with an emitter of the triode Q4, a base electrode of the triode Q4 is electrically connected with, the negative pole (Go) of non-ann's end power is connected to triode Q4 collecting electrode electricity, and non-ann's end power positive pole (Vo) electricity connecting resistance R39, resistance R39 other end electricity connecting power status indicator lamp (D17) positive terminal, and power status indicator lamp (D17) negative pole electricity is connected the negative pole (Go) of ann's end power, and non-ann's end power negative pole (Go) are connected to the 15 th foot GND electricity of non-ann's end RS232 conversion chip (U2).

6. The communication RS232 signal isolation explosion-proof safety barrier as claimed in claim 1, wherein a 13 pin R1IN of the non-intrinsic safety end RS232 conversion chip (U2) is electrically connected with a resistor R16, the other end of the resistor R16 is electrically connected with a 7 pin of the output terminal (U3C), a 14 pin T10UT of the non-intrinsic safety end RS232 conversion chip (U2) is electrically connected with a resistor R15, the other end of the resistor R15 is electrically connected with an 8 pin of the output terminal (U3C), and a 9 pin of the output terminal (U3C) is electrically connected with a negative electrode (Go) of the non-intrinsic safety end power supply.