CN108829006A - The analogue quantity output device and method of alternative output voltage or electric current - Google Patents

Abstract

The invention belongs to the technical field of electrical automation control. In order to solve the technical problem that the analog output device mentioned in the prior art cannot conveniently realize the output of different analog signals, the invention provides an analog output device that can selectively output voltage or current. A quantity output device and method, capable of selectively outputting voltage or current only by inputting different instructions; the analog quantity output device includes: an output channel, which is provided with a voltage output module and a current output module, and receives Different drive signals for selectively outputting voltage or current; a micro control unit connected to the input end of the output channel, the micro control unit inputs a voltage drive signal or a current drive signal to the output channel; wherein, when the When the micro control unit inputs a voltage drive signal, the output channel outputs a voltage; when the micro control unit inputs a current drive signal, the output channel outputs a current.

Description

Analog output device and method for selectively outputting voltage or current

technical field

The invention relates to the technical field of electrical automation control, in particular to an analog output device and method capable of selectively outputting voltage or current.

Background technique

In the instrument and control system of nuclear power plants, the analog output device, as the output control input and output node of the field control station, is the most critical module in the instrument and control system, and its performance and parameter characteristics are very important. For example, Chinese patent application number CN200910249911.7 discloses a high-reliability analog output device including: D/A conversion module, current drive output module, A/D output readback module, MCU, CPLD and communication The circuit, the current drive output module is a current driver, and the current driver is connected to the signal connector to output the current signal; it can realize the advantages of output readback detection coverage and safe output function.

And the existing analog quantity output device is usually divided into two kinds: one, for the same device, can only output voltage or output current (as mentioned in the above-mentioned patent CN200910249911.7), that is, the output type of the device is fixed, or The device can output a voltage signal, or the device can output a current signal; 2. For the same device, it can output both a voltage signal and a current signal, but it cannot output at the same time. It is necessary to select which one to output through a hardware jumper or switch signal type.

But the inventor finds in the process of realizing the present invention, the analog quantity output device of prior art has the following deficiencies:

1. The disadvantage of the first output method above is that the output type is single and the application is limited.

2. The disadvantage of the second output method above is that it is inconvenient to switch the output signal type, and it is necessary to adjust the jumper or switch and change the device form. If the device is plugged into the case, you need to pull out the device for setting; if the device includes a case, you need to open the case for setting or consider the exposed jumper or switch when designing the case structure.

Contents of the invention

In order to solve the technical problem that the analog output device mentioned in the prior art cannot conveniently realize the output of different analog signals, the present invention provides an analog output device and method that can selectively output voltage or current, which can only input Different commands can selectively output voltage or current.

In order to achieve the above object, the technical solutions provided by the invention include:

One aspect of the present invention provides an analog output device that can selectively output voltage or current, which is characterized in that it includes:

The output channel is provided with a voltage output module and a current output module, and selectively outputs voltage or current according to different driving signals received by the output channel;

a micro control unit connected to the input end of the output channel, the micro control unit inputs a voltage drive signal or a current drive signal to the output channel;

Wherein, when the input of the micro control unit is a voltage drive signal, the output channel outputs a voltage; when the input of the micro control unit is a current drive signal, the output channel outputs a current.

In an embodiment of the present invention, preferably, the device includes a plurality of output channels, and the micro-control unit is provided with drive signal output ports respectively corresponding to the plurality of output channels, so that each output channel receives a voltage drive signal or current drive signal.

In an embodiment of the present invention, preferably, the device further includes: a digital/analog signal conversion unit located between the micro-control unit and the output channel, and an analog/analog signal conversion unit connected to the output terminal of the digital/analog signal conversion unit. A digital signal conversion unit, the analog/digital signal conversion unit collects the analog signal of the digital/analog signal conversion unit, converts the analog signal into a digital signal, and feeds it back to the micro control unit.

In the embodiment of the present invention, it is further preferred that when the difference between the digital signal fed back by the analog/digital signal conversion unit and the digital signal input by the digital/analog signal conversion unit is greater than a predetermined value, the micro control unit determines that the If the output channel connected to the digital/analog signal conversion unit fails, stop the output of the digital/analog signal conversion unit.

In the embodiment of the present invention, preferably, the output terminal of the output channel is also connected to the micro control unit, and when the analog output device is in the voltage output mode, if the load is short-circuited or the load is too small, the fault indication pin is low level; when the analog output device is in the current output mode, if the load is open or the load is too large, the fault indication pin is low level.

Another aspect of the present invention also provides an analog output method for selectively outputting voltage or current, which is characterized in that it includes:

The micro control unit inputs a drive signal to the output channel;

judging whether the driving signal represents a voltage driving signal or a current driving signal;

Wherein, when the input of the micro control unit is a voltage drive signal, the output channel outputs a voltage; when the input of the micro control unit is a current drive signal, the output channel outputs a current.

In an embodiment of the present invention, preferably, the manner in which the micro-control unit inputs the drive signal to the output channel includes: the micro-control unit is provided with drive signal output ports corresponding to the plurality of output channels, so that each output channel is independently Receive a voltage or current drive signal.

In an embodiment of the present invention, preferably, the method further includes: inputting an analog signal to the output channel through a digital/analog signal conversion unit located between the micro control unit and the output channel; The analog/digital signal conversion unit connected to the output end of the analog signal conversion unit collects the analog signal of the digital/analog signal conversion unit, converts the analog signal into a digital signal, and feeds it back to the micro control unit.

In the embodiment of the present invention, it is further preferred that when the difference between the digital signal fed back by the analog/digital signal conversion unit and the digital signal input by the digital/analog signal conversion unit is greater than a predetermined value, the micro control unit determines that the If the output channel connected to the digital/analog signal conversion unit fails, stop the output of the digital/analog signal conversion unit.

In the embodiment of the present invention, preferably, when the input of the micro-control is a voltage drive signal, if the load is short-circuited or the load is too small, the fault indication pin is at a low level; when the input of the micro-control is a current drive signal , if the load is open or the load is too large, the fault indication pin is low.

By adopting the above-mentioned technical solution provided by the present application, at least one of the following beneficial effects can be obtained:

1. For the same output channel, voltage signal or current signal can be selectively output, and the output of different signal types can be switched through control commands, without changing hardware settings, easy to operate; and there is no limit to the design of the device structure.

2. When the analog output device has multiple output channels, each channel can be individually configured for voltage or current output, making it easier to control multiple output channels of the analog output device separately; so that each output channel can be configured separately , flexible application.

Other features and advantages of the invention will be set forth in the following description, and partly become obvious from the description, or can be understood by implementing the technical solution of the invention. The objectives and other advantages of the present invention can be realized and obtained by the structures and/or processes particularly pointed out in the specification, claims and accompanying drawings.

Description of drawings

FIG. 1 is a first schematic diagram of an analog output device that can selectively output voltage or current provided by an embodiment of the present invention.

FIG. 2 is a second schematic diagram of an analog output device that can selectively output voltage or current provided by an embodiment of the present invention.

FIG. 3 is a schematic diagram of an output voltage state of an output channel in an analog output device that can selectively output voltage or current provided by an embodiment of the present invention.

4 is a schematic diagram of an output current state of an output channel in an analog output device that can selectively output voltage or current provided by an embodiment of the present invention.

FIG. 5 is a schematic diagram of an analog output device that can selectively output voltage or current provided by another embodiment of the present invention.

FIG. 6 is a flow chart of an analog output method for selectively outputting voltage or current provided by an embodiment of the present invention.

Detailed ways

The implementation of the present invention will be described in detail below in conjunction with the accompanying drawings and examples, so as to fully understand and implement the process of how to apply technical means to solve technical problems and achieve technical effects in the present invention. It should be noted that these specific descriptions are only for those of ordinary skill in the art to understand the present invention more easily and clearly, rather than limiting interpretation of the present invention; and as long as there is no conflict, each embodiment and each embodiment of the present invention Each feature in the invention can be combined with each other, and the formed technical solutions are all within the protection scope of the present invention.

Additionally, the steps shown in the flowcharts of the figures may be performed in a control system, such as a set of controller-executable instructions, and, although a logical sequence is shown in the flowcharts, in some cases, may be implemented in The steps shown or described are performed in an order different than here.

Below by accompanying drawing and specific embodiment, technical solution of the present invention is described in detail:

Example

As shown in Figure 1, this embodiment provides an analog output device that can selectively output voltage or current, and the analog output device includes:

The output channel 200 is provided with a voltage output module 210 and a current output module 220, and selectively outputs voltage or current according to different driving signals received by the output channel;

The micro control unit 100 connected to the input end of the output channel 200, the micro control unit 100 inputs a voltage drive signal or a current drive signal to the output channel 200;

When the MCU 100 inputs a voltage driving signal, the output channel 200 outputs a voltage; when the MCU 100 inputs a current driving signal, the output channel 200 outputs a current.

It should be noted that the above-mentioned voltage output module 210 and current output module 220 mentioned in this embodiment can be independent modules, such as a chip with an independent output voltage signal function, and a peripheral circuit connected to the voltage signal control chip , and a chip with an independent output current signal function, and a peripheral circuit connected to the current signal control chip; according to different output requirements, input enable signals to different chips. The above-mentioned voltage output module 210 and current output module 220 can also be integrated in a chip and a peripheral circuit with both voltage output and current output functions at the same time, that is, the voltage output module 210 and the current output module 220 have overlapping partial circuits; for example, According to the received voltage input enabling signal, the formed output circuit is the voltage output module 210 ; according to the received current input enabling signal, the formed output short circuit is the current output module 220 . These different specific implementation modes all belong to the protection scope of the present application.

Among them, Microcontroller Unit (MCU for short), also known as Single Chip Microcomputer (Single Chip Microcomputer) or single-chip microcomputer, is to properly reduce the frequency and specifications of the Central Processing Unit (Central Process Unit; (memory), counter (Timer), USB, A/D conversion, UART, PLC, DMA and other peripheral interfaces, and even LCD driver circuits are integrated on a single chip to form a chip-level computer, making different combinations for different applications Control; Specifically, the micro-control unit provided by this embodiment also includes GPIO (full name General Purpose Input Output, general-purpose input/output), and GPIO product can provide control and monitoring function; For example, GPIO can output high level or low power Level, high level (or low level) can be selected as the voltage drive signal, and the enabling module corresponding to the output channel 200 will enable the voltage output module 210; and correspondingly, low level (or high level) can be selected As the current driving signal, the enabling module corresponding to the output channel 200 will enable the current output module.

As shown in Figure 2, preferably in this embodiment, the analog output device further includes: a digital/analog signal conversion unit (D/A chip) between the micro control unit and the output channel, and a digital/analog signal conversion unit The analog/digital signal conversion unit (A/D chip) connected to the output terminal, the analog/digital signal conversion unit (D/A chip) collects the analog signal of the digital/analog signal conversion unit (A/D chip), and converts the analog After the quantity signal is converted into a digital signal, it is fed back to the micro control unit. In this embodiment, further preferably, when the difference between the digital signal fed back by the analog/digital signal conversion unit (D/A chip) and the digital signal input by the digital/analog signal conversion unit (A/D chip) is greater than a predetermined value, The micro control unit (single chip microcomputer) determines that the output channel connected to the digital/analog signal conversion unit (D/A chip) is faulty, and stops the output of the digital/analog signal conversion unit.

More specifically, the microcontroller outputs a digital signal to the D/A chip through SPI0, and the D/A chip outputs an analog voltage signal after conversion. Among them, SPI is the abbreviation of Serial Peripheral Interface (Serial Peripheral Interface). SPI is a high-speed, full-duplex, synchronous communication bus, and it only occupies four wires on the pins of the chip, which saves the pins of the chip, saves space for the layout of the PCB, and provides convenience. Because of this easy-to-use feature, more and more chips integrate this communication protocol, such as AT91RM9200. On the one hand, the voltage signal output by the D/A chip is sent to the output channel, and the final required signal can be output after conditioning; on the other hand, the A/D acquisition chip converts the analog quantity into a digital quantity and sends it to the single-chip microcomputer through SPI1 as a diagnosis. basis. If the difference between the digital signal output by SPI0 and the digital signal collected by SPI1 is too large, it is considered that the channel is faulty and the D/A output is stopped. A preferred implementation in Figure 2: the voltage output module in the output channel can directly receive the analog signal output by the D/A chip after the enabling module receives the voltage drive signal input by the microcontroller, and then convert and output the corresponding The voltage; the voltage output module in the output channel, after the enabling module receives the current drive signal input by the microcontroller, directly receives the analog signal output by the D/A chip, and then converts and outputs the corresponding current.

In this embodiment, preferably, the analog output device includes a plurality of output channels, and the micro-control unit is provided with drive signal output ports (for example, a plurality of GPIO ports) respectively corresponding to the plurality of output channels, so that each output channel receives a voltage independently drive signal or current drive signal.

Of course, as an alternative implementation, it is also possible to connect multiple output channels with the same output signals (for example, under a certain condition, a voltage signal is always required for multiple channels; and under another condition, a current signal is always required) to the same GPIO port, which saves hardware resources.

As shown in Figure 2, in this embodiment, preferably, the output end of the output channel is also connected to the microcontroller unit, and when the analog output device is in the voltage output mode, if the load is short-circuited or the load is too small, the fault indication pin is Low level; when the analog output device is in the current output mode, if the load is open or the load is too large, the fault indication pin is low level. That is, if the I/O port of the single-chip microcomputer outputs a low level, the device outputs a voltage signal; the single-chip microcomputer can also detect the fault indication pin of the output channel through the I/O port to detect load faults in time. In the voltage output mode, if the load is short-circuited or the load is too small, the fault indication pin is low; in the current output mode, if the load is open or the load is too large, the fault indication pin is low.

The following describes how to selectively output a voltage signal or a current signal in the output channel according to the input signal in the embodiment of the present application in conjunction with Fig. 3 and Fig. 4:

As shown in Figure 3 and Figure 4, an existing, dedicated voltage and current output chip is provided in the output channel; the voltage and current output chip is connected to the GPIO port of the single-chip microcomputer, and the M1 and M2 of the output chip are controlled through the GPIO port of the single-chip microcomputer The pin can select voltage or current output; the specific control logic is shown in Table 1.

M1 M2 MODE (mode) L L Vout (voltage output) L h Iout (current output)

Table 1. Output channel input and output control logic relationship table

As shown in FIG. 5 , this embodiment also provides an analog output method that can selectively output voltage or current, and the analog output method includes:

S1. The micro-control unit inputs the driving signal to the output channel; specifically: a. The micro-control unit can receive the input signal of the input unit in the control unit, and then output to the output channel; b. The external input connected to the micro-control unit unit through the bus The signal input by the device is then output to the output channel; c. directly output the corresponding signal to the output channel through the specified code loaded in the memory of the micro control unit; more specific implementation: for example, the micro control unit receives through the CAN bus Communication data, which includes the output signal type (voltage or current) and output data (that is, the magnitude of the voltage or current). Then the micro control unit controls the output type of the output channel through the GPIO port on the one hand, and on the other hand sends the output data (digital quantity) to the DA (digital-to-analog conversion circuit) through SPI, and the DA (digital-to-analog conversion circuit) converts the output data into analog The amount is then given to the output channel for final output.

S2, judging whether the drive signal represents a voltage drive signal or a current drive signal; the micro-control unit or the output channel judges the type of the drive signal output by step S1, that is, whether the judgment signal is a voltage drive signal or a current drive signal; as a preferred For the ground solution, as mentioned above, the signal input by GPIO can be distinguished as a voltage-driven signal or a current-driven signal by its height. Similarly, it can also be judged whether it is a voltage-driven signal or a current-driven signal by whether the signal is high-voltage or low-voltage;

S3. When the micro control unit inputs a voltage driving signal, the output channel outputs a voltage; when the micro control unit inputs a current driving signal, the output channel outputs a current.

It should be noted that the above "when the micro control unit inputs a voltage drive signal" and "when the micro control unit inputs a current drive signal" refer to the output channel (or output chip) connected to the micro control unit It is an input signal for the MCU itself and an output signal for the MCU itself.

In this embodiment, preferably, the manner in which the micro-control unit inputs the drive signal to the output channel in step S1 of the above-mentioned analog output method includes: the micro-control unit is provided with drive signal output ports respectively corresponding to a plurality of output channels, so that each output Channels individually receive voltage or current drive signals.

Preferably in this embodiment, the above analog output method further includes: inputting an analog signal to the output channel through a digital/analog signal conversion unit located between the micro control unit and the output channel; The analog/digital signal conversion unit collects the analog signal of the digital/analog signal conversion unit, converts the analog signal into a digital signal, and feeds it back to the micro control unit. Further preferably, when the difference between the digital signal fed back by the analog/digital signal conversion unit and the digital signal input by the digital/analog signal conversion unit is greater than a predetermined value, the micro-control unit determines to output the output connected to the digital/analog signal conversion unit Channel failure, stops the output of the digital/analog signal conversion unit.

Preferably, in the above-mentioned analog quantity output method, when the micro-control input is a voltage drive signal, if the load is short-circuited or the load is too small, the fault indication pin is low level; when the micro-control input is a current drive signal , if the load is open or the load is too large, the fault indication pin will be low.

As shown in FIG. 6 , the above-mentioned analog output device or analog output method provided by this embodiment can be applied to the SpeedyHold platform of the DCS instrument control system, for example, a 4-channel analog output device is realized.

The analog output device is divided into four parts: output channel, single-chip microcomputer system, communication, and power supply; the power supply of the channel, single-chip microcomputer system, and communication are independent of each other. The analog output device has 4 output channels, the output type can be controlled through different GPIO ports, and the output type of each channel is independent; the output of D/A is read back through A/D to realize the self-diagnosis function.

Specifically, the CAN bus interface of the MCU of the analog output device is connected to the first external connector through the CAN communication bus, and the first connector can be connected to the main control unit of the DCS instrument control system; and the first connector passes through multiple The power supply module inputs the required power signal to the MCU; the MCU is also provided with the same D/A chip (DAC) and A/D chip (ADC) as in Figure 2, and the MCU and the D/A chip and the A/D chip are set There is a signal isolation device; a digital/analog signal conversion unit (D/A chip) located between the micro control unit (MCU) and the output channel, and an analog/digital signal conversion unit ( A/D chip), the analog/digital signal conversion unit (D/A chip) collects the analog signal of the digital/analog signal conversion unit (A/D chip), converts the analog signal into a digital signal, and feeds it back to the micro Control unit; when the difference between the digital signal fed back by the analog/digital signal conversion unit (D/A chip) and the digital signal input by the digital/analog signal conversion unit (A/D chip) is greater than a predetermined value, the micro control unit ( The single chip microcomputer) judges that the output channel connected to the digital/analog signal conversion unit (D/A chip) is faulty, and stops the output of the digital/analog signal conversion unit. . In addition, the MCU inputs drive signals to the four output channels through the GPIO port, and the output channels input the required voltage or current signals to the modules in the DCS instrument control system that require corresponding signals through the second connector.

By adopting the above-mentioned technical solution provided by the present application, at least one of the following beneficial effects can be obtained:

1. For the same output channel, voltage signal or current signal can be selectively output, and the output of different signal types can be switched through control commands, without changing hardware settings, easy to operate; and there is no limit to the design of the device structure.

2. When the analog output device has multiple output channels, each channel can be individually configured for voltage or current output, making it easier to control multiple output channels of the analog output device separately; so that each output channel can be configured separately , flexible application.

Those of ordinary skill in the art can understand that all or part of the steps for implementing the above method embodiments can be completed by program instructions and related hardware. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above-mentioned method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk and other various media that can store program codes.

Finally, it should be noted that the above description is only the best embodiment of the present invention, and does not limit the present invention in any form. Any person familiar with the art, without departing from the scope of the technical solution of the present invention, can make many possible changes and simple replacements to the technical solution of the present invention by using the methods and technical contents disclosed above, all of which belong to the technical solution of the present invention Scope of program protection.

Claims (10)

1. the analogue quantity output device of a kind of alternative output voltage or electric current, which is characterized in that including：

Output channel is provided with voltage output module and current output module, and according to the received different driving of output channel Signal, selectively output voltage or electric current；

The micro-control unit connecting with the output channel input terminal, the micro-control unit is to the output channel input voltage Driving signal or current drive signal；

Wherein, when the micro-control unit input be voltage drive signals when, the output channel output voltage；When described micro- When what control unit inputted is current drive signal, the output channel exports electric current.

2. the apparatus according to claim 1, which is characterized in that described device includes multiple output channels, and described micro- Control unit is provided with driving signal output end mouth corresponding with the multiple output channel respectively, so that each output channel list Solely receive voltage drive signals or current drive signal.

3. the apparatus according to claim 1, which is characterized in that further include：Positioned at the micro-control unit and the output Digital/analog signal converting unit between channel, and the mould being connect with the digital/analog signal converting unit output end Quasi-/digital signal converting unit, the analog/digital signal conversion unit acquire the digital/analog signal converting unit Analog signals, and after the analog signals are converted to digital signal, feed back to the micro-control unit.

4. device according to claim 3, which is characterized in that when the number of analog/digital signal conversion unit feedback When difference is greater than predetermined value between word signal and the digital signal of digital/analog signal converting unit input, the micro-control Unit processed determine it is described export the output channel failure that connect with the digital/analog signal converting unit, stopping it is described it is digital/ The output of analog signal converting unit.

5. the device in -4 described in any one according to claim 1, which is characterized in that the output end of the output channel also with Micro-control unit connection, and when the analogue quantity output device is in voltage output mode, if load short circuits or Load it is too small, then indicating fault pin be low level；When the analogue quantity output device is in current output mode, if load Open circuit or load excessive, then indicating fault pin is low level.

6. a kind of analog output method of alternative output voltage or electric current, which is characterized in that including：

Micro-control unit is to output channel input drive signal；

Judge the driving signal characterization is voltage drive signals or current drive signal；

Wherein, when the micro-control unit input be voltage drive signals when, the output channel output voltage；When described micro- When what control unit inputted is current drive signal, the output channel exports electric current.

7. according to the method described in claim 6, it is characterized in that, the micro-control unit is to output channel input drive signal Mode include：The micro-control unit is provided with driving signal output end mouth corresponding with the multiple output channel respectively, So that each output channel individually receives voltage or current driving signal.

8. according to the method described in claim 6, it is characterized in that, further including：By being located at the micro-control unit and described Digital/analog signal converting unit between output channel inputs analog signal to the output channel；By with the number Word/analog signal converting unit output end connection analog/digital signal conversion unit, acquires the digital/analog signal and turns The analog signals of unit are changed, and after the analog signals are converted to digital signal, feed back to the micro-control unit.

9. according to the method described in claim 8, it is characterized in that, working as the number of analog/digital signal conversion unit feedback When difference is greater than predetermined value between word signal and the digital signal of digital/analog signal converting unit input, the micro-control Unit processed determine it is described export the output channel failure that connect with the digital/analog signal converting unit, stopping it is described it is digital/ The output of analog signal converting unit.

10. the method according to any one in claim 6-9, which is characterized in that it is when microcontroller input is electricity When pressing driving signal, if load short circuits or load are too small, indicating fault pin is low level；When the microcontroller inputs Be current drive signal when, if load open circuit or load excessive, indicating fault pin be low level.