CN201133916Y - A kind of multimeter equipped with alarm function data acquisition card - Google Patents

Abstract

The utility model discloses a multimeter equipped with an alarm function data acquisition card, aiming to provide a multimeter capable of being equipped with data acquisition cards with multi-channel measurement input and multi-channel control output. The gist of its technical solution is to include a multimeter and its extension - a data acquisition card, wherein the multimeter includes a control processing module, a measurement module, a storage module, an input module, and a display module, and the data acquisition card includes a multi-channel Input access module, a multi-channel alarm output module. The input of the multi-channel input access module is connected to the multi-channel input channel, the output is connected to the input of the measurement module, and its serial communication interface is connected to the control processing module; the serial communication interface of the multi-channel alarm output module is connected to the control processing module, Its output is connected with multiple alarm outputs.

Description

A kind of multimeter equipped with alarm function data acquisition card

technical field

The utility model generally relates to the field of multimeter measurement work, and more particularly relates to the field of multimeter measurement work with a data acquisition card with extended multi-channel input and alarm output.

Background technique

A general multimeter has a voltage or resistance measurement interface and a current measurement interface. The user introduces the measurement signal into the multimeter for measurement through the test leads.

This measurement method can only be connected to one measurement point at a time. If you want to measure the voltage, resistance or current value of different points at the same time, this kind of multimeter has great limitations.

The current existing technology is shown in Figure 1, which is to expand a data acquisition card on the basis of a multimeter. This data acquisition card has many inputs, and can simultaneously access multiple voltages, resistances, and currents, and then pass through a switch matrix circuit. , at a certain moment, connect a certain input to the input of the multimeter for measurement. Although, each instant still only measures the value of one access point, if the switch matrix circuit is controlled to connect multiple inputs to the input terminals of the multimeter separately, multi-channel measurement can be realized. If the switching time is fast enough, it can give the user the impression that multiple measurements are being made simultaneously.

For example, as shown in Figure 1, at a certain moment, the multimeter controls the switch matrix circuit to connect the input HI of channel 1 to the voltage input terminal of the multimeter, and connect the input L0 of channel 1 to the ground input terminal of the multimeter. At this time, the multimeter measures the measured value of channel 1; at another moment, the multimeter controls the switch matrix circuit to connect the input HI of channel 2 to the voltage input terminal of the multimeter, and connect the input L0 of channel 2 to the ground of the multimeter At the input end, at this time, the multimeter measures the measured value of channel 2; in this way, multi-channel measurement can be realized through this data acquisition card.

But in many occasions, it is not only necessary to measure many voltages and currents, but also to control the output according to the changes of these measurements, so as to achieve the purpose of automatic control. Obviously, the existing technology can no longer meet such demands. For example, in some occasions of monitoring voltage, the multimeter of the existing technology can only monitor the change of voltage, but cannot make any control for the change of corresponding voltage, for example, when the voltage is greater than the set value , turn off the power, etc. In this way, the use occasions of the multimeter are greatly limited, and greater convenience cannot be brought to the user.

Existing technology 2: At present, some programmable controllers, that is, industrial control equipment, can also complete the functions of data collection and control output, but these industrial control equipment are generally fixed installations, and do not have the characteristics of portability and flexibility.

Utility model content

The purpose of the utility model is to overcome the deficiencies of the prior art and provide a multimeter that can be equipped with a data acquisition card with multiple measurement inputs and multiple control outputs.

The utility model provides a multimeter equipped with a data acquisition card with an alarm function. The multimeter comprises: a control processing module 10, a measurement module 8, a storage module 12, an input module 9, and a display module 11; the output of the measurement module 8 and the The control processing module 10 is connected to output digital signals to the control processing module 10; the control processing module 10 is connected to the input module 9 to receive user input information; the control processing module 10 is also connected to the storage module 12 connected to save and read system parameters and data; the control processing module 10 is also connected to the display module 11 to display system information; it is characterized in that it also includes:

Data acquisition card 1, described data acquisition card 1 comprises a multi-channel input access module 2, a multi-channel alarm output module 5;

The input of the multi-channel input access module 2 is connected with the multi-channel input channel, the output is connected with the input of the measurement module 8, and its serial communication interface is connected with the control processing module 10;

The serial communication interface of the multi-channel alarm output module 5 is connected to the control processing module 10, and its output is connected to the multi-channel alarm output.

The multi-channel input access module 2 includes an input switch matrix circuit and a 4-switch matrix control circuit 3:

The input switch matrix circuit 4 is connected to the input channel for accessing multi-channel voltage, resistance, current and other inputs; the input switch matrix circuit 4 is also connected to the output channel of the multi-channel input access module 2, Used to control the output of a voltage or resistance channel, and the output of a current channel;

Described switch matrix control circuit 3, its output is connected with switch matrix circuit 4, and switch matrix control circuit outputs high/low level in order to control the on-off of the switch of input switch matrix circuit 4; The communication interface is connected to the control processing module 10, and the control processing module 10 controls the output of the switch matrix control circuit 3 through serial communication.

The multi-channel alarm output module 5 includes an output switch matrix circuit 7 and a switch matrix control circuit 6:

The output switch matrix circuit 7 is connected to multiple alarm output channels;

Described switch matrix control circuit 6, its output is connected with output switch matrix circuit 7, and switch matrix control circuit 6 outputs high/low level in order to control the on-off of the switch of output switch matrix circuit 7; The serial communication interface is connected to the control processing module 10, and the control processing module 10 controls the output of the switch matrix control circuit 6 through serial communication.

The input module 9 is a keyboard, a mouse, a USB disk interface or a communication interface.

The display module 11 is a liquid crystal display or a plasma display.

Compared with the prior art, the utility model has the beneficial effects of:

1. The multimeter of the utility model that can be equipped with a data acquisition card with multiple measurement inputs and multiple control outputs not only has the functions of multi-channel data collection and analysis, but also has automatic control functions.

2. Compared with programmable controllers, that is, industrial control equipment, it has the advantages of portability, convenience and flexibility.

Description of drawings

The simplified block diagram of Figure 1 shows the functional block diagram of a prior art multimeter with an expansion data acquisition card

Fig. 2 has shown the functional block diagram of the present utility model

Fig. 3 has shown the schematic diagram of the utility model embodiment 1

Fig. 4 has shown the schematic diagram of the utility model embodiment 2

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described in detail.

Example 1:

A multimeter equipped with a data acquisition card with an alarm function, comprising: a multimeter and an extension part of the multimeter—a data acquisition card 20 , as shown in FIG. 3 .

The aforementioned data acquisition card 20 includes a multi-channel input access module 21 and a multi-channel alarm output module 23 .

The above-mentioned multimeter includes a measurement module 25 , a control processing module 27 , a storage module 29 , an input module 26 and a display module 28 .

The above-mentioned multiple input access module 21 includes a shift register 22 and a relay array. The switches of the relay array are respectively connected to the input channels for accessing multiple voltage, resistance, current and other inputs; the switches of the relay array are also respectively connected to the output of a voltage (resistance) channel and the output of a current channel. The coils of the relay array are respectively connected with the output of the shift register. The serial communication of the shift register 22 is connected with the control processing module 27 of the multimeter, and the control processing module 27 serially inputs the 01 (open/close) state of the relay array to the shift register 22 through the serial communication, thereby controlling the relay array coil The on and off of the current on the circuit also controls the opening/closing of the switch. Those skilled in the art know that there are many ways to realize the function of the above-mentioned multi-input access module, and this is only an example.

The above-mentioned multi-channel alarm output module 23 includes a shift register 24 and an optical coupler array. The output terminals of the optocoupler array are respectively connected with the alarm output channels. The input terminal of the photocoupler array is connected with the output of the shift register 24 . The serial communication of the shift register 24 is connected with the control processing module 27 of the multimeter, and the control processing module 27 serially inputs the 01 (on/off) state of the optical coupling array to the shift register 24 through the serial communication, thereby controlling the optical coupling The on-off of the current on the input diode also controls the on-off of the output of the optocoupler, and also controls the output high/low level of the alarm output channel. Those skilled in the art know that there are many ways to realize the alarm function of the above-mentioned multi-channel alarm output module, and this is only an example.

The above-mentioned measurement module 25 is connected to the multi-input access module 21 for receiving measured quantities such as voltage, current or resistance output by the multi-input access module 21 . The output of the measurement module 25 is connected with the control processing module 27, and the measured analog quantity is converted into a digital signal that the control processing module 27 can identify and process.

The above-mentioned control processing module 27 is connected with the output of the measuring module 25, receives the digital signal of the measuring module 25, and obtains the measured value through calculation. The control processing module 27 is connected to the multi-channel input access module 21, and the control processing module 27 controls the connection of the input channel and the output channel of the multi-channel input access module 21 through serial communication. The control processing module 27 is connected to the multi-channel alarm output module 23, and the control processing module 27 controls the output status of the output channels of the multi-channel alarm output module 23 through serial communication.

The process that the utility model realizes multi-channel input data acquisition and multi-channel alarm output control is described below, and the concrete steps are as follows:

Step 1: Through the input module, the control processing module receives the multi-channel measurement-alarm condition input by the user. For example, the user can input the measurement-alarm conditions shown in Table 1.

Table 1

Step 2: The control processing module arranges the measurement sequence and measurement time for the multi-channel input after analysis according to the multi-channel measurement-alarm condition input by the user. For example, for the measurement-alarm condition shown in Figure 1, the control processing module will assign:

The first measurement-alarm period is: measure input channel 1, output alarm channel k, and the duration is 1s.

The second measurement-alarm period is: measure input channel 2, output alarm channel 2, and the duration is 2s.

The third measurement—alarm period is: measure input channel n, output alarm channel 1, and the duration is 1s.

Step 3: The control processing module starts to execute sequentially according to the allocation in step 2. If it is in the cyclic execution mode, it starts to execute from the first measurement-alarm cycle after executing all the measurement-alarm cycles. For example, for the measurement-alarm condition shown in Figure 1, the control processing module first measures the first measurement-the alarm period, and the duration is 1s; then performs the second measurement-the alarm period, and the duration is 2s; then executes the first Three measurements—alarm period, the duration is 1s; then re-execute the first measurement—alarm period, and so on.

Describe below that the utility model completes the above-mentioned first measurement-the process of the alarm period, and the concrete steps are as follows:

Step 1: The control processing module controls the high/low level of each output terminal of the shift register through the serial communication interface connection with the shift register of the multi-channel input access module according to the task of the current measurement-alarm period, thereby controlling Which output channel to connect an input to. For example, as shown in Figure 3, the control processing module sequentially inputs bits to the shift register of the multi-channel input access module through the serial communication interface, controls out1 and out_volt to output high levels, and the other outputs are all low levels, At this point, the voltage (resistance) of channel 1 is introduced into the input terminal of the voltage (resistance) of the multimeter. At this time, the measurement is the input of the first channel.

Step 2: The measuring module measures the value of the input analog quantity and converts it into a digital signal; the control processing module reads the digital signal to obtain the measured value.

Step 3: The control processing module judges whether the alarm condition is met according to the measured value. And send the measurement result and whether to alarm to the display module for display.

Step 4: If the alarm condition is satisfied, the control processing module controls a certain output of the multi-channel alarm output module to output an alarm through the serial communication connection; if the alarm condition is not satisfied, the control processing module controls the multi-channel alarm through the serial communication connection A certain output of the output module turns off the alarm output. For example, the alarm condition at this time is: when the input voltage of channel 1 is greater than 3V, the channel k of the multi-channel alarm output module outputs an alarm-high level; if the input voltage of channel 1 is less than or equal to 3V, the multi-channel Channel k of the alarm output module does not output an alarm—low level. If, at this time, the measured voltage of channel 1 is 4.5V, an alarm should be output according to the alarm condition. The control processing module sequentially inputs bits to the shift register of the multi-channel alarm output module through the serial communication interface, controls outk to output a high level, and then the output k of the multi-channel alarm output module will output a high level to generate an alarm signal.

Example 2: Displacement measured by a Hall displacement sensor

A multimeter equipped with a data acquisition card with an alarm function, comprising: a multimeter and an extension part of the multimeter—a data acquisition card 40 , as shown in FIG. 4 .

The aforementioned data acquisition card 40 includes a multi-channel input access module 41 and a multi-channel alarm output module 43 .

The above multimeter includes a measurement module 45 , a control processing module 49 , a storage module 48 , an input module 46 and a display module 47 .

The above-mentioned multi-channel input access module 41 includes a single-chip microcomputer 42 and a relay array. The switches of the relay array are respectively connected to the input channels for accessing multiple voltage, resistance, current and other inputs; the switches of the relay array are also respectively connected to the output of a voltage (resistance) channel and the output of a current channel. The coils of the relay array are respectively connected with the I/O ports of the microcontroller. The serial communication interface of the single-chip microcomputer 42 is connected with the control processing module 49 of the multimeter, and the control processing module 49 sends the control command of the I/O port state to the single-chip microcomputer 42 through serial communication, thereby controlling the high/low level of the I/O Output, thereby controlling the on-off of the current on the coil of the relay array, which also controls the opening/closing of the switch. Those skilled in the art know that there are many ways to realize the function of the above-mentioned multi-input access module, and this is only an example.

The above-mentioned multi-channel alarm output module 43 includes a single-chip microcomputer 44 and a relay array. The output terminals of the relay array are respectively connected with the alarm output channels. The input end of the relay array is connected with the I/O port of the single-chip microcomputer 44 . The serial communication interface of the single-chip microcomputer 44 is connected with the control processing module 49 of the multimeter, and the control processing module 49 sends the control command of the I/O port state to the single-chip microcomputer 44 through serial communication, thereby controlling the high/low level of the I/O Output, thereby controlling the on-off of the current on the coil of the relay array, which also controls the opening/closing of the switch. Those skilled in the art know that there are many ways to realize the above-mentioned alarm function of the multi-channel alarm output module 43, and this is only an example.

The above-mentioned measurement module 45 is connected with the multi-input access module 41 to receive measured quantities such as voltage, current or resistance output by the multi-input access module. The output of the measurement module 45 is connected with the control processing module 49, and the measured analog quantity is converted into a digital signal that can be recognized and processed by the control processing module.

The above-mentioned control processing module 49 is connected with the output of the measurement module 45, receives the digital signal of the measurement module 45, and obtains the measurement value through calculation. The control processing module 49 is connected to the multi-channel input access module 41, and the control processing module 49 controls the connection of the input channel and the output channel of the multi-channel input access module 41 through serial communication. The control processing module 49 is connected to the multi-channel alarm output module 43, and the control processing module 49 controls the output status of the output channels of the multi-channel alarm output module 43 through serial communication.

The process that the utility model realizes multi-channel input data acquisition and multi-channel alarm output control is described below, and the concrete steps are as follows:

Step 1: Through the input module, the control processing module receives the multi-channel measurement-alarm condition input by the user. For example, the user may input a measurement-alarm condition as shown in Table 1.

Step 2: The control processing module arranges the measurement sequence and measurement time for the multi-channel input after analysis according to the multi-channel measurement-alarm condition input by the user. For example, for the measurement-alarm condition shown in Figure 1, the control processing module will assign:

The first measurement-alarm period is: measure input channel 1, output alarm channel k, and the duration is 1s.

The second measurement-alarm period is: measure input channel 2, output alarm channel 2, and the duration is 2s.

The third measurement—alarm period is: measure input channel n, output alarm channel 1, and the duration is 1s.

Step 3: The control processing module starts to execute sequentially according to the allocation in step 2. If it is in the cyclic execution mode, it starts to execute from the first measurement-alarm cycle after executing all the measurement-alarm cycles. For example, for the measurement-alarm condition shown in Figure 1, the control processing module first measures the first measurement-the alarm period, and the duration is 1s; then performs the second measurement-the alarm period, and the duration is 2s; then executes the first Three measurements—alarm period, with a duration of 1s; then re-execute the first measurement—alarm period, and so on;

If it is not a cyclic execution mode, the measurement is stopped after the last measurement-alarm period is executed.

Describe below that the utility model completes the above-mentioned first measurement-the process of the alarm period, and the concrete steps are as follows:

Step 1: The control processing module controls the high/low level of each I/O port of the single-chip microcomputer through the serial communication interface connection with the single-chip microcomputer of the multi-channel input access module according to the task of the current measurement-alarm period, so as to control the Which output channel a certain input is connected to. For example, as shown in Figure 4, the control processing module sends the control command of the I/O port to the single-chip microcomputer of the multi-channel input access module through the serial communication interface, controls I/O_1 and I/O_volt to output high level, and the rest The outputs are all low level. At this time, the voltage (resistance) of channel 1 is introduced into the input terminal of the voltage (resistance) of the multimeter. At this time, the measurement is the input of the first channel.

Step 2: The measuring module measures the value of the input analog quantity and converts it into a digital signal; the control processing module reads the digital signal to obtain the measured value.

Step 3: The control processing module judges whether the alarm condition is met according to the measured value. And send the measurement result and whether to alarm to the display module for display.

Step 4: If the alarm condition is satisfied, the control processing module controls a certain output of the multi-channel alarm output module to output an alarm through the serial communication connection; if the alarm condition is not satisfied, the control processing module controls the multi-channel alarm through the serial communication connection A certain output of the output module turns off the alarm output. For example, the alarm condition at this time is: when the input voltage of channel 1 is greater than 3V, the channel k of the multi-channel alarm output module outputs an alarm-high level; if the input voltage of channel 1 is less than or equal to 3V, the multi-channel Channel k of the alarm output module does not output an alarm—low level. If, at this time, the measured voltage of channel 1 is 4.5V, an alarm should be output according to the alarm condition. The control processing module sends the control command of the I/O port to the single-chip microcomputer of the multi-channel alarm output module through the serial communication interface, and controls I/O_k to output a high level, then the output k of the multi-channel alarm output module will output a high level, Generate an alarm signal.

The above specific embodiments are only used to illustrate the present utility model, but not to limit the present utility model.

Claims (5)

1. a multimeter that is equipped with the alarm function data collecting card comprises control treatment module, measurement module, memory module, load module, display module; The output of described measurement module links to each other with control treatment module, gives control treatment module in order to the output digital signal; Described load module is connected with control treatment module, in order to the information that is provided with to control treatment module input user; Described memory module is connected with control treatment module, in order to preservation, reading system parameter and data; Described display module is connected with control treatment module, in order to display system information; It is characterized in that also comprising:

Data collecting card, described data collecting card comprise multichannel input access module, multichannel alarm output module;

The input of described multichannel input access module links to each other with input multiplexer, and output links to each other with the input of measurement module, and its serial communication interface links to each other with control treatment module;

The serial communication interface of described multichannel alarm output module links to each other with control treatment module, and its output links to each other with multichannel alarm output.

2. a kind of multimeter that is equipped with the alarm function data collecting card according to claim 1 is characterized in that: described multichannel input access module comprises input switch matrix circuit and switch matrix control circuit:

Described input switch matrix circuit links to each other with input channel, in order to inputs such as the voltage that inserts multichannel, resistance, electric currents; Described switch matrix circuit also links to each other with the output channel of multichannel input access module, in order to controlling the output of voltage or resistance via, and the output of a current channel;

Described switch matrix control circuit, its output links to each other with the input switch matrix circuit, and the switch matrix control circuit is exported the break-make of high/low level in order to the switch of control input switch matrix circuit; The serial communication interface of switch matrix control circuit links to each other with control treatment module.

3. according to a kind of multimeter that is equipped with the alarm function data collecting card of claim 1, it is characterized in that:

Described multichannel alarm output module comprises matrix switch output circuit and switch matrix control circuit:

Described matrix switch output circuit links to each other with multichannel alarm output channel;

Described switch matrix control circuit, its output links to each other with switch matrix circuit, and the switch matrix control circuit is exported the break-make of high/low level in order to the switch of control matrix switch output circuit; The serial communication interface of switch matrix control circuit links to each other with control treatment module.

4. according to a kind of multimeter that is equipped with the alarm function data collecting card of claim 1, it is characterized in that:

Described load module is keyboard, mouse, USB flash disk interface or communication interface.

5. according to a kind of multimeter that is equipped with the alarm function data collecting card of claim 1, it is characterized in that:

Described display module is LCDs or plasma panel.

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