CN114779125A - Digital quantity output loop disconnection diagnosis device and diagnosis method - Google Patents
Digital quantity output loop disconnection diagnosis device and diagnosis method Download PDFInfo
- Publication number
- CN114779125A CN114779125A CN202210451204.1A CN202210451204A CN114779125A CN 114779125 A CN114779125 A CN 114779125A CN 202210451204 A CN202210451204 A CN 202210451204A CN 114779125 A CN114779125 A CN 114779125A
- Authority
- CN
- China
- Prior art keywords
- mos switch
- stage mos
- detection module
- controller
- stage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/54—Testing for continuity
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/58—Testing of lines, cables or conductors
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
- Arrangements For Transmission Of Measured Signals (AREA)
Abstract
The invention discloses a digital quantity output loop disconnection diagnosis device, comprising: a direct current power supply; two MOS switches connected in series, a front stage MOS switch K1 and a rear stage MOS switch K2; the direct current power supply outputs a positive power supply voltage and a driving current after passing through the front-stage MOS switch and the rear-stage MOS switch in sequence; an external load is connected with a cable to be diagnosed, and the driving current returns to the ground after passing through the load; the controller sends out high or low level control signals and respectively controls the on and off of the two MOS switches connected in series through the corresponding signal isolators; and the broken line detection module is connected with the preceding stage MOS switch in parallel and outputs a digital signal to the controller. The diagnosis device can detect the disconnection fault of the cable in time when the external load is in a power-on or power-off state, and the technology adopts switching value detection, has lower cost and can meet the application of larger load variation range.
Description
Technical Field
The invention relates to a cable circuit diagnosis and implementation method of a digital quantity output loop in an automation product.
Background
In industrial automation production application, DCS and PLC products are used in large quantities, and if a digital output module is required to be capable of normally outputting signals to drive equipment, cable disconnection diagnosis is essential. The traditional digital quantity output cable diagnosis scheme uses series-connected current detection resistors to differentially acquire a current signal of a loop to an analog-to-digital converter or convert the current signal into a voltage signal to a comparator for judgment and identification.
However, when the variation range of the external load is large, the variation range of the current in the loop is also large, and in order to ensure the normal work of the diagnosis function, a high-precision device is required to complete the identification, so that the hardware cost is greatly increased.
Disclosure of Invention
In order to solve the above problems, the present invention provides a digital output circuit disconnection diagnosis apparatus and a diagnosis method, which can detect a cable disconnection fault in time when an external load is in a power-on or power-off state, and which employs switching value detection, is low in cost, and can satisfy an application with a large load variation range.
The technical scheme provided by the invention is as follows:
a digital quantity output loop disconnection diagnosis device includes:
a direct current power supply;
two MOS switches connected in series, a front stage MOS switch K1 and a rear stage MOS switch K2; the direct current power supply outputs a positive power supply voltage and a driving current after passing through the front-stage MOS switch and the rear-stage MOS switch in sequence; the external load is connected with the cable to be diagnosed, and the driving current returns to the ground after passing through the load;
the controller sends out high or low level control signals and respectively controls the on and off of the two MOS switches connected in series through the corresponding signal isolators;
and the broken line detection module is connected with the preceding stage MOS switch in parallel and outputs a digital signal to the controller.
More specifically, the positive end of the direct current power supply is connected with the s pole of the front stage MOS switch, the d pole of the MOS switch is connected with the s pole of the rear stage MOS switch, the d pole of the rear stage MOS switch is connected with the diagnosed cable and outputs positive voltage of the power supply and driving current, the external load is connected with the diagnosed cable, and the driving current flows into the load from the positive end of the load, flows out from the negative end of the load and returns to the ground;
the output IO port of the controller is connected with the input end of the signal isolator and sends a high or low level control signal to the signal isolator, and the output ends of the 2 signal isolators are respectively connected with the g poles of the 2 MOS switches; and the broken line detection module is connected with the s pole and the d pole of the preceding stage MOS switch and outputs a digital signal to an IO port of the controller.
Further, the power supply is 24V direct current or 48V direct current.
Furthermore, the 2 MOS switches are all PMOS, and when the gate and source voltages of the MOS switches are 0, the MOS switches are turned off; when the grid and source voltage of the MOS switch is less than 0, the MOS switch is conducted; the controller controls the rear-stage MOS switch to be switched on or switched off, and correspondingly enables the load to be powered on or powered off. When the rear-stage switch is kept closed, the controller controls the front-stage switch to be closed or turned off, and the broken line detection module outputs an identification signal to the input port of the controller.
Furthermore, in the disconnection detection module, a key device is an optical coupler, an input end of the optical coupler is connected in series with a current-limiting resistor and then connected in parallel with an s pole and a d pole of the preceding stage MOS switch, and an output end of the optical coupler is connected with an input IO port of the controller. When the front-stage MOS switch and the rear-stage MOS switch are closed, the voltage drop of the front-stage MOS switch is very small, almost no current exists at the input end of the optical coupler, and the output of the optical coupler is turned off. The rear stage MOS switch keeps closed, when the front stage MOS switch is turned off, the current flows through the optical coupler, and the output end of the optical coupler is closed.
Further, the signal isolator is an optical coupler. And the input end of the optical coupler is connected with the output IO port of the controller. The output end of the optical coupler is connected with the g pole of the MOS switch.
The invention also provides a digital quantity output loop disconnection diagnosis method, which comprises the following steps:
1) when the external load is normally applied in an electrified mode, the controller controls the front-stage MOS switch K1 and the rear-stage MOS transistor K2 to be kept closed, and the output of the disconnection detection module U4 is turned off. During diagnosis, the controller controls the K1 to be switched off and switched on periodically, if the external cable is normal, the U4 correspondingly outputs a switching-on signal and a switching-off signal to the input port of the controller, and if the external cable is disconnected, the U4 constantly outputs the switching-off signal. The turn-off duration of the K1 is very short, less than 2ms, and the normal operation of the load cannot be influenced;
2) when the external load is normally applied in a power-off state, the controller controls the K1 and the K2 to be kept disconnected, and the output of the disconnection detection module U4 is turned off. In the diagnosis process, the controller controls the K2 to be switched off and switched on periodically, if the external cable is normal, the U4 correspondingly outputs a switching-off signal and a switching-on signal to the input port of the controller, and if the external cable is disconnected, the U4 constantly outputs a switching-off signal. The closing time of the K2 is very short, less than 2ms, and the normal operation of the load is not influenced.
The invention has the beneficial effects that: when the equipment works, the cable can be continuously and periodically diagnosed on line, and no matter the external load works in a power-on or power-off state, the alarm can be given in time when the fault occurs. The invention is suitable for a large external load range which can be from 4mA to 1A, and has low realization cost.
Drawings
FIG. 1 is a schematic diagram of the construction of the diagnostic device of the present invention;
FIG. 2 is a detailed schematic diagram of signal isolators U2 or U3 of FIG. 1;
fig. 3 is a detailed schematic diagram of the break line detection module U4 of fig. 1.
Detailed Description
The invention will be further described with reference to the accompanying drawings.
Referring to fig. 1, the digital output loop disconnection diagnosis device of the present invention includes a dc power supply Vcc, a controller U1, signal isolators U2 and U3, a front PMOS switch K1, a rear PMOS switch K2, and a disconnection detection module U4, and performs cable disconnection diagnosis by connecting to a cable to be diagnosed and an external load R.
As shown in FIG. 2, the signal isolator U2 or U3 adopts an optical coupler, inputs a positive terminal controller IO port and inputs a negative terminal controller U1 ground. The output negative terminal is connected with the ground of the direct current power supply Vcc. The positive output end is connected with 2 resistors R3 and R4 which are connected in series and then connected with the positive end of a direct current power supply. The connection of 2 series resistors is connected with the g pole of the corresponding PMOS switch. The voltage of Vg also changes as the optocoupler is turned on and off.
As shown in fig. 3, the disconnection detecting module U4 includes a key device optical coupler K3, a positive input side terminal of K3 is connected to the current limiting resistor R2, and has a resistance of 2K Ω, the other end of R2 is connected to the s pole of the preceding stage MOS switch K1, and a negative input side terminal of K3 is connected to the d pole of the preceding stage MOS switch K1. K1 is in parallel relationship with the input side of K3. The negative end of the output side of the K3 is connected with the ground of the controller U1, the positive end of the output side is connected with a pull-up resistor R1, meanwhile, the negative end is input into the IO port of the controller, and the pull-up resistor is connected with the positive end of the power supply of the controller.
The input side current of the optocoupler K3 can be normally conducted within the range of 1mA to 50mA, and the voltage drop of an internal diode at the input end of the K3 is about 1V when the optocoupler K3 is conducted. The conduction resistance of the preceding stage MOS switch is 0.1 Ω. When the 2 MOS switches K1 and K2 of the loop are closed, the load is electrified, and the maximum allowable current of the loop design is 1A. Because the current limiting resistor R2 at the input side of K3 is 2K omega, the minimum current is 1mA, the maximum voltage drop of the front stage MOS switch is only 0.1V, and the voltage drop of the diode at the input end of K3 is not calculated, the current at the input side of K3 is far less than 1mA, and the output side is turned off.
The allowed current range of the load design is 4 mA-1A, the direct current power supply voltage is 24V or 48V, and the load resistance value range is 24 omega-6K omega or 48 omega-12K omega. The controller controls the front stage MOS switch K1 to be turned off, and the rear stage MOS switch K2 to be kept closed: when the direct current power supply is 24V, the current range of the input side of the K3 is about 3mA to 12 mA; when the DC power supply is 48V, the current range of the input side of the K3 is about 6mA to 24mA, and the current range is within the input current range when the K3 is conducted, so that the output conduction requirement of the K3 is met, and the disconnection diagnosis function can be completed.
When cable diagnosis is carried out, when an external load is normally applied in an electrified mode, the controller controls the rear-stage MOS transistor K2 to be closed, and controls K1 to be turned off and closed periodically; when the external load is normally a power loss application, the controller control K1 remains open and the controller control K2 is periodically turned off and on.
If the external cable is normal, the U4 correspondingly outputs closing and closing signals to the input port of the controller; if the external cable is disconnected, the U4 constantly outputs a shutdown signal.
The foregoing is only a preferred embodiment of this invention and it should be noted that modifications can be made by those skilled in the art without departing from the principle of the invention and these modifications should also be considered as the protection scope of the invention.
Claims (7)
1. A digital quantity output circuit disconnection diagnosis device, comprising:
a direct current power supply;
a signal isolator;
two MOS switches connected in series, a front stage MOS switch and a rear stage MOS switch; the direct current power supply outputs positive power supply voltage and driving current after sequentially passing through the front stage MOS switch and the rear stage MOS switch; the external load is connected with the cable to be diagnosed, and the driving current returns to the ground after passing through the load;
the controller sends out high or low level control signals and respectively controls the on and off of the two MOS switches which are connected in series through the corresponding signal isolators;
and the broken line detection module is connected with the preceding stage MOS switch in parallel and outputs a digital signal to the controller.
2. The digital quantity output loop disconnection diagnostic device according to claim 1, wherein the former stage MOS switch and the latter stage MOS switch are both PMOS; when the grid and source voltage of the MOS switch is 0, the MOS switch is turned off; when the grid and source voltage of the MOS switch is less than 0, the MOS switch is conducted; when the external load is applied by power, the controller controls the rear-stage MOS switch to be kept closed and controls the front-stage MOS switch to be periodically closed and closed; when the external load is applied in a power-off state, the controller controls the front-stage MOS switch to be kept turned off and controls the rear-stage MOS switch to be turned on and off periodically; the controller controls the turn-off duration of the front-stage MOS switch or the rear-stage MOS switch to be less than 2 ms.
3. The digital quantity output loop disconnection diagnostic device according to claim 2, wherein the disconnection detection module employs an optical coupler, an input end of the optical coupler is connected in series with a current-limiting resistor and then connected in parallel with an s pole and a d pole of the pre-stage MOS switch, and an output end of the optical coupler is connected with an input IO port of the controller.
4. The digital quantity output loop disconnection diagnostic device according to claim 3, wherein the signal isolators each employ an optical coupler, an input end of each optical coupler is connected with an output IO port of the controller, and an output end of each optical coupler is connected with the g-stage of the corresponding MOS switch.
5. The digital quantity output loop disconnection diagnostic device of claim 4, wherein the DC power supply is DC 24V or DC 48V.
6. The digital quantity output loop disconnection diagnostic device according to claim 5, wherein a current limiting resistor connected in series with an optocoupler of the disconnection detection module is 2K Ω.
7. A method for diagnosing disconnection of a digital output circuit using the diagnostic apparatus as set forth in claim 1, wherein the method comprises:
when the external load is normally applied by power, the controller controls the front stage MOS switch and the rear stage MOS switch to be kept closed, and the output of the broken line detection module is turned off; in the diagnosis process, the controller controls the preceding stage MOS switch to be turned off and turned on periodically, and receives the identification signal of the disconnection detection module through the controller to diagnose the cable: when the disconnection detection module outputs a closing signal and a closing signal correspondingly, the external cable is diagnosed to be normal, and when the disconnection detection module outputs a closing signal constantly, the external cable is diagnosed to be disconnected;
when the external load is normally applied in a power-off state, the controller controls the front-stage MOS switch and the rear-stage MOS switch to be kept disconnected, and the output of the disconnection detection module is switched off; in the diagnosis process, the controller controls the rear-stage MOS switch to be periodically switched off and switched on, and the controller receives the identification signal of the disconnection detection module to diagnose the cable: and when the disconnection detection module outputs the closing and closing signals correspondingly, the external cable is diagnosed to be normal, and when the disconnection detection module outputs the closing signal constantly, the external cable is diagnosed to be disconnected.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210451204.1A CN114779125A (en) | 2022-04-24 | 2022-04-24 | Digital quantity output loop disconnection diagnosis device and diagnosis method |
| PCT/CN2023/077133 WO2023207279A1 (en) | 2022-04-24 | 2023-02-20 | Disconnection diagnosis apparatus and method for digital quantity output loop |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210451204.1A CN114779125A (en) | 2022-04-24 | 2022-04-24 | Digital quantity output loop disconnection diagnosis device and diagnosis method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114779125A true CN114779125A (en) | 2022-07-22 |
Family
ID=82433507
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210451204.1A Pending CN114779125A (en) | 2022-04-24 | 2022-04-24 | Digital quantity output loop disconnection diagnosis device and diagnosis method |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN114779125A (en) |
| WO (1) | WO2023207279A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115865062A (en) * | 2023-02-20 | 2023-03-28 | 浙江国利信安科技有限公司 | Digital quantity output module |
| WO2023207279A1 (en) * | 2022-04-24 | 2023-11-02 | 南京科远智慧科技集团股份有限公司 | Disconnection diagnosis apparatus and method for digital quantity output loop |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63217280A (en) * | 1987-03-05 | 1988-09-09 | Tatsuta Electric Wire & Cable Co Ltd | Method and device for detecting wire breaking of electric wire cable |
| CN104270126A (en) * | 2014-09-10 | 2015-01-07 | 国家电网公司 | On-off output circuit, control method and monitoring method |
| CN106066446A (en) * | 2016-06-29 | 2016-11-02 | 南京国电南自美卓控制系统有限公司 | A kind of multichannel analog amount input circuit break detection circuit and method |
| CN107783525A (en) * | 2017-11-22 | 2018-03-09 | 国核自仪系统工程有限公司 | DI dynamic diagnosis circuits based on FPGA |
| WO2019226171A1 (en) * | 2018-05-25 | 2019-11-28 | Siemens Industry, Inc. | Fault detection in power supply to a load in terms of a broken wire detection for a functional safety dc output |
| CN109062169B (en) * | 2018-10-10 | 2021-02-09 | 中核控制系统工程有限公司 | High-reliability switching value signal acquisition system and acquisition method thereof |
| CN110007663A (en) * | 2019-05-14 | 2019-07-12 | 中国核动力研究设计院 | The output switch parameter dynamic diagnostics system and method for nuclear safe level DCS |
| CN110347143B (en) * | 2019-08-07 | 2020-10-16 | 中国核动力研究设计院 | Nuclear safety level optimization module field drive output loop diagnosis system and method |
| CN212965358U (en) * | 2020-05-18 | 2021-04-13 | 惠州市蓝微电子有限公司 | Broken line detection circuit with load access automatic wake-up function and power bank |
| CN111813088B (en) * | 2020-07-16 | 2021-10-01 | 国核自仪系统工程有限公司 | DI channel diagnostic circuit and method |
| CN112180219B (en) * | 2020-10-13 | 2024-02-27 | 南京科远智慧科技集团股份有限公司 | Cable circuit of industrial digital quantity output loop and implementation method |
| CN213149533U (en) * | 2021-04-08 | 2021-05-07 | 成都运达科技股份有限公司 | Hardware two-out-of-three voting circuit and train LCU control system |
| CN114779125A (en) * | 2022-04-24 | 2022-07-22 | 南京科远智慧科技集团股份有限公司 | Digital quantity output loop disconnection diagnosis device and diagnosis method |
-
2022
- 2022-04-24 CN CN202210451204.1A patent/CN114779125A/en active Pending
-
2023
- 2023-02-20 WO PCT/CN2023/077133 patent/WO2023207279A1/en unknown
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023207279A1 (en) * | 2022-04-24 | 2023-11-02 | 南京科远智慧科技集团股份有限公司 | Disconnection diagnosis apparatus and method for digital quantity output loop |
| CN115865062A (en) * | 2023-02-20 | 2023-03-28 | 浙江国利信安科技有限公司 | Digital quantity output module |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2023207279A1 (en) | 2023-11-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114779125A (en) | Digital quantity output loop disconnection diagnosis device and diagnosis method | |
| CN107065716B (en) | Digital quantity acquisition circuit with dynamic fault diagnosis capability | |
| CN109254245B (en) | Relay loop short circuit and open circuit detection circuit | |
| CN109166744B (en) | Dual-power automatic transfer switch and transfer control method thereof | |
| CN113866666A (en) | High-voltage interlocking circuit and fault detection method thereof | |
| CN103669252B (en) | A kind of gate automatically | |
| CN104422896A (en) | Method and device for detecting direct current crossing in double direct-current power source systems | |
| CN113506706B (en) | Contactor driving circuit with high reliability and working method | |
| CN207992860U (en) | Digital output circuit and industrial control equipment | |
| CN112180219B (en) | Cable circuit of industrial digital quantity output loop and implementation method | |
| CN110008069A (en) | Power supply control switching circuit and control method | |
| CN212811274U (en) | H-bridge protection module, motor driving device and dish washing machine | |
| CN104331340A (en) | Watchdog circuit | |
| CN214409212U (en) | Relay switch state detection circuit with direct-current voltage injection | |
| CN111289882B (en) | Push-pull output PWM open circuit detection circuit and method and vehicle | |
| CN213986774U (en) | Railway signal cable integrity and state on-line monitoring device | |
| CN212845895U (en) | Voltage comparator module circuit in short-circuit fault warning device of ammeter | |
| CN111541440B (en) | Switching value input circuit suitable for nonpolar multi-level voltage input | |
| CN207764922U (en) | A kind of system of electric power terminal device instruction operation troubles | |
| CN216121903U (en) | Low-loss redundancy operation circuit of switching power supply | |
| CN113311357A (en) | Alternating-current charging stake short circuit detection circuitry | |
| CN112255540A (en) | Adhesion fault detection circuit of low-side contactor | |
| CN219420288U (en) | Protection circuit for preventing relay misoperation caused by signal abnormality | |
| CN215267712U (en) | Drive circuit for lithium battery control switch | |
| CN110460011A (en) | A kind of short-circuit protection circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |