CN102315844B - Digital quantity output device of programmable logic controller and self-checking method - Google Patents
Digital quantity output device of programmable logic controller and self-checking method Download PDFInfo
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Abstract
The invention provides a self-checking method for a digital quantity output device of a programmable logic controller, and the method comprises the following steps: collecting the digital quantity output when a driving switching tube is in a turn-on state/off state in the digital quantity output device according to a selected signal transmitted by an I/O (input/output) module processing unit in the digital quantity output device; carrying out a differential operation to the collected digital quantity output and the supply voltage of the driving switching tube to obtain a simulation signal for representing the turn-on voltage drop/electricity leakage judgment parameter of the driving switching tube; converting the simulation signal into a digital signal; and comparing the digital signal with the turn-on voltage drop parameter value of the driving switching tube/the voltage value which is the same to the power supply of the driving switching tube, thereby judging whether the driving switching tube is aged or not. Correspondingly, the embodiment of the invention also provides a digital quantity output device of a programmable logic controller. According to the digital quantity output device provided by the invention, the recession conditions of the driving switching tube can be known in advance, and users can perform equipment maintenance before cataleptic failures.
Description
Technical field
The present invention relates to automation control area, relate in particular to a kind of digital quantity output device of programmable logic controller and self checking method.
Background technology
Programmable logic controller (PLC) (PLC, Programmable Logic Controller) digital quantity (switching value) of controlling consumption in the system of a middle scale surpasses 1,000 points, wherein output point accounts for half left and right, therefore the reliability of digital output is related to the reliability of whole automation application system, and some output points in these digital outputs are being controlled the equipment position, key of system, and system is very harsh to the reliability requirement of the output point of these significant points.
In prior art, digital output point is general all to be controlled by power switch, and the reliability of these output points determines by the durability of power switch substantially, when power switch lost efficacy because the reason such as aging breaks down, often is not easy to aware.In prior art, a kind of improved plan is to increase feedback loop to these output points, in order to reach alarm after detecting output abnormality, is convenient to the maintenance of system.
Yet above way is in the situation that the reaction just made of fault of output point, and often caused loss without redemption to industrial production this time.
Summary of the invention
The technical problem that lags behind for the failure monitoring that solves digital output point in prior art, the embodiment of the present invention provides a kind of digital quantity output device of programmable logic controller, comprise: I/O modular processing unit and at least one driving switch pipe, each driving switch pipe is connected with described I/O modular processing unit by a photoisolator, this driving switch pipe drives digital output under the control of described I/O modular processing unit, described device also comprises: multiplexer, difference amplifier unit and analog to digital converter, wherein:
Described I/O modular processing unit is connected with described multiplexer and described analog to digital converter respectively by a signal isolated location, the digital output when the described driving switch pipe of select-out signal collection that described multiplexer sends according to described I/O modular processing unit is in conducting state;
Described difference amplifier unit is connected between described multiplexer and described analog to digital converter, the output of wherein said multiplexer is as an input of described difference amplifier unit, and another input of described difference amplifier unit is the voltage input identical with described driving switch pipe power supply;
Described analog to digital converter is to send to described I/O modular processing unit after digital signal with the analog signal conversion of the sign driving switch pipe conduction voltage drop of described difference amplifier unit output, the conduction voltage drop parameter value of the driving switch pipe that prestores in described digital signal and I/O modular processing unit is compared, whether aging to judge the driving switch pipe.
The conduction voltage drop parameter value of the driving switch pipe that wherein, prestores in described I/O modular processing unit comprises: the standard conduction voltage drop value of each driving switch pipe under the nominal operation state or the limit conduction voltage drop value of each driving switch pipe.
Wherein, described I/O modular processing unit is connected with the primary processor of programmable logic controller (PLC) by communication port.
Wherein, also store the work state information of each driving switch pipe in described I/O modular processing unit, described work state information reads for the programmable logic controller (PLC) primary processor that is connected with described I/O modular processing unit, described work state information comprises ageing state and normal condition, when the digital signal of sending according to described analog to digital converter when described I/O modular processing unit was judged certain driving switch pipe and is in ageing state, the work state information of this driving switch pipe was set to ageing state.
Accordingly, the embodiment of the present invention also provides a kind of digital quantity output device of programmable logic controller, comprise: I/O modular processing unit and at least one driving switch pipe, each driving switch pipe is connected with described I/O modular processing unit by a photoisolator, this driving switch pipe drives digital output under the control of described I/O modular processing unit, described device also comprises: multiplexer, difference amplifier unit and analog to digital converter, wherein:
Described I/O modular processing unit is connected with described multiplexer and described analog to digital converter respectively by a signal isolated location, the digital output when the described driving switch pipe of select-out signal collection that described multiplexer sends according to described I/O modular processing unit is in cut-off state;
Described difference amplifier unit is connected between described multiplexer and described analog to digital converter, the output of wherein said multiplexer is as an input of described difference amplifier unit, and another input of described difference amplifier unit is the voltage input identical with described driving switch pipe power supply;
Described analog to digital converter is to send to described I/O modular processing unit after digital signal with the analog signal conversion of the sign driving switch pipe electric leakage judgement parameter of described difference amplifier unit output, the magnitude of voltage identical with driving switch pipe power supply of storing in described digital signal and I/O modular processing unit compared, whether aging to judge the driving switch pipe.
Wherein, described I/O modular processing unit is connected with the primary processor of programmable logic controller (PLC) by communication port.
Wherein, also store the work state information of each driving switch pipe in described I/O modular processing unit, described work state information reads for the programmable logic controller (PLC) primary processor that is connected with described I/O modular processing unit, described work state information comprises ageing state and normal condition, when the digital signal of sending according to described analog to digital converter when described I/O modular processing unit was judged certain driving switch pipe and is in ageing state, the work state information of this driving switch pipe was set to ageing state.
Accordingly, the embodiment of the present invention also provides a kind of self checking method of digital quantity output device of programmable logic controller, comprising:
The digital output when select-out signal that sends according to the I/O modular processing unit in described digital quantity output device gathers driving switch pipe in described digital quantity output device and is in conducting state/cut-off state;
The digital output of described collection and the supply voltage of described driving switch pipe are made calculus of differences, obtain characterizing the analog signal of driving switch pipe conduction voltage drop/electric leakage judgement parameter;
Be digital signal with described analog signal conversion;
The conduction voltage drop parameter value of described digital signal and driving switch pipe/magnitude of voltage identical with driving switch pipe power supply compared, whether aging to judge the driving switch pipe.
Wherein, the conduction voltage drop parameter value of described driving switch pipe comprises: the standard conduction voltage drop value of each driving switch pipe under the nominal operation state or the limit conduction voltage drop value of each driving switch pipe.
Wherein, described method also comprises:
Be that each driving switch pipe is equipped with a work state information, described work state information comprises ageing state and normal condition, and when judging certain driving switch pipe and be in ageing state, the work state information of this driving switch pipe is set to ageing state.
Implement the embodiment of the present invention, the digital output the when select-out signal that sends according to the I/O modular processing unit in described digital quantity output device gathers driving switch pipe in described digital quantity output device and is in conducting state/cut-off state; The digital output of described collection and the supply voltage of described driving switch pipe are made calculus of differences, obtain characterizing the analog signal of driving switch pipe conduction voltage drop/electric leakage judgement parameter; Be digital signal with described analog signal conversion; The conduction voltage drop parameter value of described digital signal and driving switch pipe/magnitude of voltage identical with driving switch pipe power supply compared, to judge whether the driving switch pipe is aging, can understand in advance the Decline State of driving switch pipe, make the user can carry out plant maintenance before catastrophic failure.
Description of drawings
In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, the below will do to introduce simply to the accompanying drawing of required use in embodiment or description of the Prior Art, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.
Fig. 1 is a kind of structural representation of digital quantity output device of programmable logic controller in the embodiment of the present invention;
Fig. 2 is the flow chart that utilizes the device in Fig. 1 that each driving switch pipe is patrolled and examined in the embodiment of the present invention;
Fig. 3 is the schematic flow sheet of a kind of self checking method of digital quantity output device of programmable logic controller in the embodiment of the present invention.
Embodiment
The embodiment of the present invention provides a kind of self checking method of digital quantity output device of programmable logic controller, can understand in advance the device Decline State, thereby makes the user carry out plant maintenance before driving switch pipe catastrophic failure.
Describe embodiments of the invention in detail below in conjunction with accompanying drawing.
Referring to Fig. 1, be a kind of structural representation of digital quantity output device of programmable logic controller in the embodiment of the present invention.Described digital quantity output device comprises: I/O modular processing unit 10 and at least one driving switch pipe, wherein the I/O modular processing unit is the input/output module processing unit, only show three railway digital amount outputs in Fig. 1, therefore only show three driving switch pipes, as driving switch pipe 20, driving switch pipe 21, driving switch pipe 22 in figure.Each driving switch pipe is connected with described I/O modular processing unit 10 by a photoisolator, and in Fig. 1, driving switch pipe 20 is connected with described I/O modular processing unit 10 by photoisolator 30; Driving switch pipe 21 is connected with described I/O modular processing unit 10 by photoisolator 31; Driving switch pipe 22 is connected with described I/O modular processing unit 10 by photoisolator 32.Described each driving switch pipe drives digital output under the control of described I/O modular processing unit 10, the supply voltage of each driving switch pipe is the DC POWER in Fig. 1.In Fig. 1, a1, a2, am are the digital output control signal of I/O modular processing unit 10 outputs, A1, A2, Am are the digital output that the driving switch pipe drives, and described device also comprises: multiplexer 40, difference amplifier unit 50 and analog to digital converter 60, wherein:
described I/O modular processing unit 10 is connected with described multiplexer 40 and described analog to digital converter 60 respectively by a signal isolated location 70, the select-out signal C1 that described multiplexer 40 sends according to described I/O modular processing unit 70 gathers the digital output of described driving switch pipe, the A1 ' in Fig. 1 wherein, A2 ', Am ' controls collection signal for digital output, the select-out signal C1 that sends when described I/O modular processing unit 70 is when gathering the digital output of driving switch pipe 20 outputs, multiplexer 40 passes through A1 ' digital output and controls the digital output that collection signal gathers described driving switch pipe 20, digital output of multiplexer 40 each collections, the digital output that each driving switch pipe 20 is exported can adopt the mode of patrolling and examining collection to carry out.
described difference amplifier unit 50 is connected between described multiplexer 40 and described analog to digital converter 60, the output of wherein said multiplexer 40 is as an input of described difference amplifier unit, another input of described difference amplifier unit 50 is the voltage input DC POWRE identical with described driving switch pipe power supply, what carry out in described difference amplifier unit 50 is the difference computing of supply voltage DC POWRE and the digital output that selected channels drive switching tube is exported of driving switch pipe, when described multiplexer 40 gather be the digital output of selected channels drive switching tube when being in conducting state the time, obtain characterizing the corresponding analog signal of selecting the driving switch pipe conduction voltage drop VDS (on) of passage,
Described analog to digital converter 60 is to send to described I/O modular processing unit 10 after digital signal with the analog signal conversion of described difference amplifier unit 50 outputs, described digital signal characterizes respectively the work at present characteristic of each driving switch pipe, the conduction voltage drop parameter value of the associated drives switching tube that prestores in described digital signal and I/O modular processing unit 10 is compared, whether aging to judge the driving switch pipe.
The conduction voltage drop parameter value of the driving switch pipe that prestores in described I/O modular processing unit 10 comprises: the standard conduction voltage drop value of each driving switch pipe under the nominal operation state or the limit conduction voltage drop value of each driving switch pipe.When the parameter that prestores in described I/O modular processing unit 10 is the standard conduction voltage drop value of driving switch pipe under the nominal operation state, digital signal and the described standard conduction voltage drop value of analog to digital converter 60 outputs are compared, if both have difference but difference is less, represent that the driving switch pipe has degradation to a certain degree, but do not affect the stability of output signal, therefore do not need to safeguard, exceeded certain scope and work as both differences, just judge this driving switch pipe degradation be on the verge of collapse, need maintenance immediately; The parameter that prestores in described I/O modular processing unit 10 is the limit conduction voltage drop value of each driving switch pipe, when the digital signal of the work at present characteristic of each driving switch pipe of sign of analog to digital converter 60 output has surpassed described limit conduction voltage drop value, represent the driving switch pipe degradation need repairing.
Described I/O modular processing unit is connected by the primary processor of communication port with programmable logic controller (PLC) PLC.If this PLC digital quantity output device is the digital output of PLC expansion module, I/O module handler unit by external communication ports with is connected the primary processor of outside PLC and connects.If the output point of this PLC digital quantity output device is the output point that PLC carries, be connected primary processor and connect in I/O module handler unit with internal PLC by the intercommunication port.
Also store the work state information of each driving switch pipe in described I/O modular processing unit, described work state information reads for the PLC primary processor that is connected with described I/O modular processing unit, described work state information comprises ageing state and normal condition, when the digital signal of sending according to described analog to digital converter when described I/O modular processing unit was judged certain driving switch pipe and is in ageing state, the work state information of this driving switch pipe was set to ageing state.During enforcement, described work state information can be a work condition state word that is equipped with for each output channel in described I/O modular processing unit, initial value can be set to 0, when judgment result is that certain driving switch pipe is in ageing state, the work condition state word assignment that this driving switch pipe is corresponding is 1, the PLC primary processor can read this work condition state word, when the work condition state word that reads is 1, send alarm signal, notify this driving switch pipe degradation of user to be on the verge of collapse, need keep in repair immediately.
Implement the embodiment of the present invention, to the driving switch pipe whether aging detection can be that some driving switch pipes to appointment detect, also can adopt the passage at each driving switch pipe place is patrolled and examined sampling, patrolling and examining the frequency of sampling can set according to demand for the user, such as 50 hertz, namely patrol and examine each second 50 times, when the device in adopting the embodiment of the present invention was patrolled and examined sampling, the process of self-test of the PLC digital quantity output device with self-checking function in the present invention can be referring to Fig. 2.
In addition, can also be according to digital signal and the described standard conduction voltage drop value difference size relatively of analog to digital converter 60 outputs, ageing state is divided a plurality of grades, such as unaged, slightly aging, mittlere alterung, serious aging (can collapse at any time), multiple alarm signal is set in the work condition state word accordingly, can according to the application scenario of digital quantity output device, does more careful monitoring to the ageing state of switching tube like this.Such as in the high Industry Control occasion of reliability requirement, switching tube just should in time be changed after mittlere alterung.
Certainly, except the conduction voltage drop when the conducting judges aging or failure state with the pilot switch pipe according to above-described switching tube, can also judge according to other indexs of detection degree of aging or the no inefficacy of switching tube, electrical leakage voltage when ending such as switching tube or leakage current, if electrical leakage voltage or leakage current have surpassed certain amount, just can the alarm switch tube failure, this also need to prestore in I/O modular processing unit 10 corresponding specified electrical leakage voltage reduced parameter or leakage current reduced parameter.When judging whether by electrical leakage voltage when aging, the electrical leakage voltage reduced parameter that prestores in I/O modular processing unit 10 can be the magnitude of voltage identical with driving switch pipe power supply, it is the DC POWER value in Fig. 1, at this moment, described multiplexer 40 gathers is the digital output (electrical leakage voltage) of selected channels drive switching tube when being in cut-off state, and what carry out in difference amplifier unit 50 that the difference amplifier obtains is the analog signal that characterizes the driving switch pipe electric leakage judgement parameter of corresponding selected passage.
It should be explained that, there is a small leakage current in general switching tube under cut-off state, and so-called electrical leakage voltage is the voltage corresponding with leakage current.Drain electrode and the poor VDS of source voltage (off) when the electrical leakage voltage reduced parameter that is defined, essence are the switching tube cut-off, because there is electrical leakage voltage, its value is more smaller than supply voltage DC power.I/O modular processing unit 10 is in relatively, if find that electrical leakage voltage reduced parameter and supply voltage DC power difference are larger, illustrate that electric leakage is comparatively serious, indicated the degree of aging of switching tube, when difference reaches certain set point, and may be defined as the collapse alarm status.
Need to prove in addition, it is in the nature the aanalogvoltage with a certain size magnitude of voltage for so-called digital quantity, usually represents its logic state with 0 or 1.In the embodiment of the present invention, being digital output although we gather, is the aanalogvoltage of a certain size magnitude of voltage of gathering in fact, therefore can carry out calculus of differences to it, and then compare in I/O modular processing unit 10 after changing digital quantity into.
Referring to Fig. 2, the flow chart for the device that utilizes in the embodiment of the present invention in Fig. 1 is patrolled and examined each driving switch pipe comprises the steps:
Wherein, the corresponding digital quantity output channel of each driving switch pipe, represent to work as prepass with CH, with chlbuf[CH] expression driving switch pipe conduction voltage drop VDS (on), the limit conduction voltage drop value that represents the driving switch pipe with MAX_VDS, STA[CH] expression work condition state, i.e. work state information.
Step S101: the current channel number of initialization, CH:=passage 1, initialization chlbuf[CH] be full 0, suppose MAX_VDS:=2.6V;
Step S102: the variable connector that multiplexer is set is conducting to the CH passage;
Step S103: the digital output of the CH passage that multiplexer collects obtains characterizing the analog signal of selected channels drive switching tube conduction voltage drop VDS (on) after the computing of difference transport and placing device, starting analog-to-digital conversion (being the AD conversion), is digital signal with described analog signal conversion;
Step S104:I/O modular processing unit reads the result of analog to digital converter conversion, and deposits in chlbuf[CH after being converted into voltage];
Step S105: with chlbuf[CH] compare with MAX_VDS;
If chlbuf[CH]＞the MAX_VDS establishment, work condition state STA[CH] :=" alarm ";
Other situations: STA[CH] :=" normally ".
Step S106: step S101 has detected a passage that the driving switch pipe is corresponding to step S105, and step S106 carries out assignment to CH, judges at first whether current channel number is last channel number, if so, and CH:=1, if not, CH:=CH+1; After the channel number assignment is complete, return to step 102, the variable connector of multiplexer is conducting to CH passage after assignment, patrol and examine successively the passage at each driving switch pipe place, to determine the residing state of each driving switch pipe, in time understand its degradation state before the aging collapse of driving switch pipe, carry out plant maintenance before driving switch pipe catastrophic failure.
The above has introduced in the embodiment of the present invention structure with the PLC digital quantity output device of self-checking function, introduces the self checking method of PLC digital quantity output device in the embodiment of the present invention below in conjunction with Fig. 3.
Referring to Fig. 3, be the schematic flow sheet of the self checking method of a kind of digital quantity output device of programmable logic controller in the embodiment of the present invention, described method comprises the steps:
Step S201: the select-out signal that sends according to the I/O modular processing unit in described digital quantity output device gathers the digital output when in described digital quantity output device, the driving switch pipe is in conducting state, the collection of digital output is that multiplexer carries out, under the control of select-out signal, digital output of the each collection of multiplexer, multiplexer can adopt the mode of patrolling and examining collection to the collection of digital output; The time of collection output is after the stable output of switching tube, rather than in the moment of switching tube action, gathers and constantly can be controlled by PLC, and the erroneous judgement that may bring of can avoiding like this fluctuating is broken.In addition, if what the output of switching tube connected is inductive load, in order to prevent that inductive load is to the interference of collection signal, can be to being output signal and inductive load is isolated, perhaps the signal that gathers is carried out filtering, or to the output signal sampling of delaying time, the impact that will avoid load to bring in a word, thus avoid possible erroneous judgement disconnected.
Step S202: the digital output of described collection and the supply voltage of described driving switch pipe are made calculus of differences, obtain characterizing the analog signal of driving switch pipe conduction voltage drop VDS (on);
Step S203: be digital signal with the analog signal conversion of described sign driving switch pipe conduction voltage drop VDS (on), described digital signal characterizes respectively the work at present characteristic of each driving switch pipe;
Step S204: the conduction voltage drop parameter value of described digital signal and driving switch pipe is compared, whether aging to judge the driving switch pipe.The conduction voltage drop parameter value of described driving switch pipe comprises: the standard conduction voltage drop value of each driving switch pipe under the nominal operation state or the limit conduction voltage drop value of each driving switch pipe.When the conduction voltage drop parameter value of driving switch pipe is the standard conduction voltage drop value of driving switch pipe under the nominal operation state, described digital signal and described standard conduction voltage drop value are compared, if both differences are less, represent that the driving switch pipe has degradation to a certain degree, but do not affect the stability of output signal, therefore do not need to safeguard, exceeded certain scope and work as both differences, just judge this driving switch pipe degradation be on the verge of collapse, need maintenance immediately; When the conduction voltage drop parameter value of driving switch pipe is the limit conduction voltage drop value of each driving switch pipe, if described digital signal has surpassed described limit conduction voltage drop value, represent the driving switch pipe degradation need repairing.
Certainly, except the conduction voltage drop when the conducting judges aging or failure state with the pilot switch pipe according to above-described switching tube, can also judge according to other indexs of detection degree of aging or the no inefficacy of switching tube, electrical leakage voltage when ending such as switching tube or leakage current, if electrical leakage voltage or leakage current have surpassed certain amount, just can the alarm switch tube failure, this need to prestore in I/O modular processing unit 10 corresponding specified electrical leakage voltage or leakage current reduced parameter.when judging whether by electrical leakage voltage when aging, the electrical leakage voltage reduced parameter that prestores in the I/O modular processing unit can be the magnitude of voltage identical with driving switch pipe power supply, it is the DC POWER value in Fig. 1, at this moment, described multiplexer collection be the digital output (electrical leakage voltage) of selected channels drive switching tube when being in cut-off state, what the difference amplifier obtained is the analog signal that characterizes the driving switch pipe electric leakage judgement parameter of corresponding selected passage, difference by contrast driving switch pipe electric leakage judgement parameter and POWER value, can judge the switching tube aging conditions.
in the absolute stable situation of supply voltage value, difference amplifier step in the embodiment of the present invention can be cancelled, digital output (electrical leakage voltage) when the selected channels drive switching tube of multiplexer collection this moment is in cut-off state, and the electrical leakage voltage parameter that prestores in the I/O modular processing unit, described electrical leakage voltage parameter comprises the standard electrical leakage voltage value of each driving switch pipe under the nominal operation state or the limit electrical leakage voltage value of each driving switch pipe, can judge by the difference that contrasts both whether the driving switch pipe is aging, as: at the driving switch pipe under normal circumstances, its electrical leakage voltage should be near 0V, when electrical leakage voltage reaches certain threshold value (as 2V), just represent that the driving switch pipe is in ageing state, replacing needs repairing.But in reality, the impossible absolute stability of supply voltage for the error that prevents that power-supply fluctuation from bringing, therefore needs the poor designs partite transport to stride suddenly.
In order to facilitate the PLC primary processor to read driving switch pipe current state, described method also comprises:
Be that each driving switch pipe is equipped with a work state information in the I/O modular processing unit, described work state information comprises ageing state and normal condition, when judging certain driving switch pipe and be in ageing state, the work state information of this driving switch pipe is set to ageing state.During enforcement, described work state information can be for being the work condition state word that the output channel at each driving switch pipe place is equipped with in described I/O modular processing unit, initial value can be set to 0, when judgment result is that certain driving switch pipe is in ageing state, the work condition state word assignment that this driving switch pipe is corresponding is 1, the PLC primary processor can read this work condition state word, when the work condition state word that reads is 1, send alarm signal, notify the user to need this driving switch pipe degradation to be on the verge of collapse, need keep in repair immediately.
Implement the embodiment of the present invention, the digital output the when select-out signal that sends according to the I/O modular processing unit in described digital quantity output device gathers driving switch pipe in described digital quantity output device and is in conducting state/cut-off state; The digital output of described collection and the supply voltage of described driving switch pipe are made calculus of differences, obtain characterizing the analog signal of driving switch pipe conduction voltage drop/electric leakage judgement parameter; Be digital signal with described analog signal conversion; The conduction voltage drop parameter value of described digital signal and driving switch pipe/magnitude of voltage identical with driving switch pipe power supply compared, to judge whether the driving switch pipe is aging, can understand in advance the Decline State of driving switch pipe, make the user carry out plant maintenance before driving switch pipe catastrophic failure.
Above disclosed is only a kind of preferred embodiment of the present invention, certainly can not limit with this interest field of the present invention, and the equivalent variations of therefore doing according to claim of the present invention still belongs to the scope that the present invention is contained.
Claims (10)
1. digital quantity output device of programmable logic controller, comprise: I/O modular processing unit and at least one driving switch pipe, each driving switch pipe is connected with described I/O modular processing unit by a photoisolator, this driving switch pipe drives digital output under the control of described I/O modular processing unit, it is characterized in that, described device also comprises: multiplexer, difference amplifier unit and analog to digital converter, wherein:
Described I/O modular processing unit is connected with described multiplexer and described analog to digital converter respectively by a signal isolated location, the digital output when the described driving switch pipe of select-out signal collection that described multiplexer sends according to described I/O modular processing unit is in conducting state;
Described difference amplifier unit is connected between described multiplexer and described analog to digital converter, the output of wherein said multiplexer is as an input of described difference amplifier unit, and another input of described difference amplifier unit is the voltage input identical with described driving switch pipe power supply;
Described analog to digital converter is to send to described I/O modular processing unit after digital signal with the analog signal conversion of the sign driving switch pipe conduction voltage drop of described difference amplifier unit output, the conduction voltage drop parameter value of the driving switch pipe that prestores in described digital signal and I/O modular processing unit is compared, whether aging to judge the driving switch pipe.
2. device as claimed in claim 1, it is characterized in that, the conduction voltage drop parameter value of the driving switch pipe that prestores in described I/O modular processing unit comprises: the standard conduction voltage drop value of each driving switch pipe under the nominal operation state or the limit conduction voltage drop value of each driving switch pipe.
3. device as claimed in claim 2, is characterized in that, described I/O modular processing unit is connected with the primary processor of programmable logic controller (PLC) by communication port.
4. device as claimed in claim 3, it is characterized in that, also store the work state information of each driving switch pipe in described I/O modular processing unit, described work state information reads for the primary processor of the programmable logic controller (PLC) that is connected with described I/O modular processing unit, described work state information comprises ageing state and normal condition, when the digital signal of sending according to described analog to digital converter when described I/O modular processing unit was judged certain driving switch pipe and is in ageing state, the work state information of this driving switch pipe was set to ageing state.
5. digital quantity output device of programmable logic controller, comprise: I/O modular processing unit and at least one driving switch pipe, each driving switch pipe is connected with described I/O modular processing unit by a photoisolator, this driving switch pipe drives digital output under the control of described I/O modular processing unit, it is characterized in that, described device also comprises: multiplexer, difference amplifier unit and analog to digital converter, wherein:
Described I/O modular processing unit is connected with described multiplexer and described analog to digital converter respectively by a signal isolated location, the digital output when the described driving switch pipe of select-out signal collection that described multiplexer sends according to described I/O modular processing unit is in cut-off state;
Described difference amplifier unit is connected between described multiplexer and described analog to digital converter, the output of wherein said multiplexer is as an input of described difference amplifier unit, and another input of described difference amplifier unit is the voltage input identical with described driving switch pipe power supply;
Described analog to digital converter is to send to described I/O modular processing unit after digital signal with the analog signal conversion of the sign driving switch pipe electric leakage judgement parameter of described difference amplifier unit output, the magnitude of voltage identical with driving switch pipe power supply of storing in described digital signal and I/O modular processing unit compared, whether aging to judge the driving switch pipe.
6. device as claimed in claim 5, is characterized in that, described I/O modular processing unit is connected with the primary processor of programmable logic controller (PLC) by communication port.
7. device as claimed in claim 6, it is characterized in that, also store the work state information of each driving switch pipe in described I/O modular processing unit, described work state information reads for the primary processor of the programmable logic controller (PLC) that is connected with described I/O modular processing unit, described work state information comprises ageing state and normal condition, when the digital signal of sending according to described analog to digital converter when described I/O modular processing unit was judged certain driving switch pipe and is in ageing state, the work state information of this driving switch pipe was set to ageing state.
8. the self checking method of a digital quantity output device of programmable logic controller, is characterized in that, comprising:
The digital output when select-out signal that sends according to the I/O modular processing unit in described digital quantity output device gathers driving switch pipe in described digital quantity output device and is in conducting state/cut-off state;
The digital output of described collection and the supply voltage of described driving switch pipe are made calculus of differences, obtain characterizing the analog signal of driving switch pipe conduction voltage drop/electric leakage judgement parameter;
Be digital signal with described analog signal conversion;
The conduction voltage drop parameter value of described digital signal and driving switch pipe/magnitude of voltage identical with driving switch pipe power supply compared, whether aging to judge the driving switch pipe.
9. method as claimed in claim 8, is characterized in that, the conduction voltage drop parameter value of described driving switch pipe comprises: the standard conduction voltage drop value of each driving switch pipe under the nominal operation state or the limit conduction voltage drop value of each driving switch pipe.
10. method as claimed in claim 9, is characterized in that, described method also comprises:
Be that each driving switch pipe is equipped with a work state information, described work state information comprises ageing state and normal condition, and when judging certain driving switch pipe and be in ageing state, the work state information of this driving switch pipe is set to ageing state.
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| CN103645730B (en) * | 2013-12-09 | 2016-01-13 | 成都乐创自动化技术股份有限公司 | A kind of motion control card with self-checking function and detection method |
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| CN109557892A (en) * | 2017-09-26 | 2019-04-02 | 株洲中车时代电气股份有限公司 | A kind of DIO channel status detection method and embedded test system |
| CN111181180B (en) * | 2018-06-07 | 2021-07-27 | 安徽南瑞中天电力电子有限公司 | Multifunctional automatic phase changing system and method for medium and low voltage line |
| CN109709863B (en) * | 2019-01-05 | 2024-03-08 | 深圳市合信达控制系统有限公司 | AD port self-checking circuit of singlechip, singlechip and water heater |
| CN109671406A (en) * | 2019-01-09 | 2019-04-23 | 惠科股份有限公司 | Gamma chip, display panel driving circuit and display device |
| CN109947087A (en) * | 2019-04-17 | 2019-06-28 | 湖南优利泰克自动化系统有限公司 | PLC input/output module test method, device, system and computer equipment |
| CN110045652B (en) * | 2019-04-23 | 2024-06-14 | 苏州爱科赛博电源技术有限责任公司 | Positive and negative control compatible digital input circuit of electric automobile controller |
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| CN101372919A (en) * | 2008-09-02 | 2009-02-25 | 北京理工大学 | Electronic control unit for diesel electric-controlled high pressure common rail injection system |
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| US7170315B2 (en) * | 2003-07-31 | 2007-01-30 | Actel Corporation | Programmable system on a chip |
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| CN1112493A (en) * | 1995-05-12 | 1995-11-29 | 清华大学 | Energy-saving and auxiliary driving monitoring and controlling device for electric vehicle |
| CN2519346Y (en) * | 2001-12-31 | 2002-10-30 | 仪垂杰 | Interface data collector |
| CN101372919A (en) * | 2008-09-02 | 2009-02-25 | 北京理工大学 | Electronic control unit for diesel electric-controlled high pressure common rail injection system |
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