CN201509188U - Intelligent conversion device for simulating current and on-site bus signals - Google Patents

Abstract

The utility model discloses an intelligent conversion device for simulating current and on-site bus signals, which belongs to the field of the industrial automation, and comprises a conversion module, a main module, a display module and software; the main module is respectively connected with the conversion module and the display module, and a traditional simulation signal instrument is switched onto a WorldFIP on-site bus through the main module. The device has the functions of intelligentization, input signal automatic correction, non-linear compensation, digital filter and the like, has self-testing and self-diagnosis function, can correct and overcome the error and interference which are brought by different simulation current devices so as to improve the measurement conversion precision and to improve the informatization degree.

Description

The Intelligent Switching Device of analog current and fieldbus signal

Technical field

The utility model belongs to the industrial automation field, particularly a kind of analog current of field bus technique Application and Development on product and the Intelligent Switching Device of fieldbus signal.

Background technology

Field bus technique Application and Development on product does not also form the product line of a great variety of goods, perfect in shape and function; Owing to have multiple standard for Fieldbus at present, make existing product can't satisfy user's needs fully, so the instrument of the fieldbus specification that does not also have on some temporary transient markets can only be used conventional 4～20mA signalling arrangement.The another one important reasons is that for the user, although field bus system has so many advantages, engineering cost also is whether they adopt one of Consideration of this product.The fieldbus intelligence instrument exceeds about 15% than the conventional instrument price at present, in with respect to the scattered control system that can use non intelligent instrument (DCS), even after considering the saving of elements such as interface card and cable, the spending of field bus system hardware still may increase to some extent than the DCS that uses non intelligent instrument, so some users are also ready to use non intelligent instrument to reduce investment outlay in unessential position.The 3rd, for project reconstruction, many conventional 4～20mA signalling arrangements can't be discarded without exception, must utilize the original conventional 4～20mA signalling arrangement of part, so a kind of " mixed type " scheme is a kind of solution of system digitalized transformation very economically and reasonably in present stage.To this, way that well solves be by a kind of conversion equipment with traditional analog signal instrument " switching " to fieldbus, like this, the various advantages of field bus technique had both been brought into play, provide cost savings greatly again simultaneously, particularly, can utilize existing analog signal instrument well for system reform user.

Summary of the invention

The purpose of this utility model is at there being multiple standard for Fieldbus in the prior art at present, the deficiency that makes existing product can't satisfy user's needs fully provides the Intelligent Switching Device of a kind of analog current and fieldbus signal, it is characterized in that, this Intelligent Switching Device be a kind of be the conversion equipment of WorldFIP fieldbus numeral signal with 4～20mA normalized current conversion of signals, described Intelligent Switching Device comprises modular converter, primary module, display module and software design thereof; Primary module is connected with modular converter, display module respectively.

Described primary module comprises microprocessor, communication module and communications interface unit; The address bus A[0:8 of communication module] with data address multiplex bus AD[0:7] be connected the address bus A[0:8 of microprocessor respectively] and D[0:7], and with microprocessor internal memory chip route selection ground connection.

Described modular converter comprises that variable connector, signal condition, A/D converter and Signal Spacing constitute,

Described display module selects for use character type LCD lattice module to make display device; Be connected with microprocessor bus by parallel interface.

The beneficial effects of the utility model, this device can be transferred to widely used rule 4～20mA signalling arrangement in the blind controller system on the WorldFIP fieldbus, traditional analog signalling is dissolved in the numerical control system of networking, make full use of existing equipment and realized the transformation of system, greatly reduce cost and investment; Have following characteristics:

1) this device has intellectuality, has input signal from functions such as dynamic(al) correction, nonlinear compensation, digital filterings, revise and overcome the sum of errors that all kinds of analog current equipment that are connected introduce and disturb, thereby improved device the measurement conversion accuracy;

2) this device has self-test and self-diagnostic function, can be the user by fieldbus networks diagnostic message is provided, and has improved the level of informatization of installing self;

3) have extendible controlled function on the spot, designed functional block application software in the device, for condition has been created in the realization based on the full distributed control of field bus technique based on the functional block configuration technology.

Description of drawings

Fig. 1 is the structure of Intelligent Switching Device.

Fig. 2 is modular converter structure and composition.

Fig. 3 analog/digital converter ADS1110.

Fig. 4 is the AT91M40800 structure.

Fig. 5 is the microprocessor submodule design drawing of primary module.

Fig. 6 is the communicator module of Intelligent Switching Device.

Fig. 7 is the connecting circuit of microprocessor module and communicator module.

Fig. 8 is the connecting circuit of the microprocessor submodule of display module and primary module.

Embodiment

The utility model is the Intelligent Switching Device of analog current and fieldbus signal.Below in conjunction with accompanying drawing the present invention is illustrated.

Figure 1 shows that the structure of Intelligent Switching Device.Described Intelligent Switching Device comprises modular converter, primary module, display module and software design thereof.Primary module is connected with modular converter, display module respectively, and primary module with traditional analog signal instrument " switching " to the WorldFIP fieldbus, promptly the analog current signal of the 4～20mA that gathers is converted to the digital signal that meets the WorldFIP field bus protocol, finish with fieldbus between communicate by letter; Finish real-time calculating simultaneously, Kong Zhi basic task on the spot,

Figure 2 shows that the modular converter structure.Comprise that variable connector, signal condition, A/D converter and Signal Spacing constitute, the major function of modular converter is with the 4～20mA standard signal from conventional instrument, through signal condition, be converted to the voltage that is fit to the A/D converter conversion, after Signal Spacing, be sent to master module processes with the form of digital quantity.Wherein the function of variable connector is that the signal of a plurality of passages is transmitted on the road common data line.The multiplexer MUX that the design selects for use adopts eight of Fairchild company production to select a chip CD4051BC, can from the input of eight tunnel analog quantitys, select any one the road from the output of pin COM end to the control of three control pin A, B, C and enable signals by CPU.The leading indicator that A/D converter should be considered when selecting is resolution, quantization error, linearity error, electrical error of null position, change-over time etc.Comprehensive above various indexs have adopted 16 analog/digital converter ADS1110 in device, can fully guarantee conversion accuracy.As shown in Figure 3.

Primary module comprises microprocessor, communication module and communications interface unit:

(1) microprocessor

In the selection of user microprocessor, select the AT91M40800 of atmel corp for use, integrated ARM7TDMI nuclear, embedded ICE interface, memory and peripheral components (as shown in Figure 4), AT91M40800 inside mainly contain two buses: AS bus (Advanced System Bus) and advanced peripheral bus APB (Advanced Peripheral Bus).ARM7TDMI is by the interconnection of interior 32 bit memories of realization of ASB interface and sheet, outside bus interface EBI and AMBA bridge.

The versatility of user microprocessor and the extensibility of function when design, have been taken into full account.On the micro-control unit plate of primary module, expanded 256KB * 16bit Flash, 256KB * 16bit SRAM and 16KBEEPROM.20 parallel interfaces have been expanded, during isolating, it have four parallel interfaces to isolate with high speed photo coupling 6N137, three isolation outputs as microprocessor, a input as microprocessor, these 4 parallel interfaces are used as the interface (realizing the SPI function) with D/A or A/D.And on microprocessor board, designed an isolation+5V and-the 5V power supply, be used for need isolating the device power supply of power supply to input/output board.The microprocessor Design figure of primary module as shown in Figure 5.

(2) communication module

The design of communication module mainly be WorldFIP fieldbus communications module and link device thereof selection be connected.Need at different scenes, there is polytype WorldFIP field bus communication controller available,, amount of communication data less communication unit such as intelligence sensor, intelligent regulator or on-the-spot PLC comparatively simple for function can select low-cost and wieldy MICROFIP chip; For needs perfect in shape and function, the big communication unit of amount of communication data such as communication control unit, then can select the FULLFIP2 chip.The designed Intelligent Switching Device of this patent uses as basic station after being connected into the WorldFIP fieldbus networks, so communication controler adopts the MICROFIP chip as communication controler, we have adopted the communicate configuration of 1M in design.The composition of communication module as shown in Figure 6.

(3) microprocessor and communication module is connected

The address bus A[0:8 of MICROFIP] with data address multiplex bus AD[0:7] respectively with the address bus A[0:8 of AT91M40800] with D[0:7] link to each other, the internal storage chip selection signal line ground connection of MICROFIP, both adopt the exchange message of sharing 512 byte memorys.Communication controler MICROFIP selects the microprocessor work pattern for use, interrupts the application of application signal alignment microprocessor by one and interrupts; All can trigger interruption when using variable, send manufacturing variables, message transfer and receiving sync id when on the WorldFIP network, receiving.The connecting circuit of microprocessor and communication module as shown in Figure 7.

Described display module selects for use character type LCD lattice module to make display device; The pin of display module comprises 8 bit data signal DB[7:0] and three tunnel control signals: read-write R/W, chip selection signal E, register selection signal RS.The connecting circuit of the microprocessor submodule of display module and primary module as shown in Figure 8.

Be connected with microprocessor bus by parallel interface.The LCD module as required, can show various possible data according to the signal that comes autonomous module, can also show various fault messages etc. simultaneously.Adopted a kind of character type LCD lattice module HD44780 in this device, can provide the drive signal of LCD display to be connected with microprocessor bus with a simple parallel interface, its volume is little, in light weight, low in energy consumption, reliability is high.Can show 192 kinds of characters of 5 * 7 fonts, 32 kinds of characters of 5 * 10 fonts can self-editing 8 (5 * 7 points) or 4 (5 * 10 points) kind character.The command function of this module is strong, and the various inputs of one-tenth capable of being combined, demonstration, displacement mode are to satisfy different requirements, and the form of demonstration is also very flexible, and many different sizes are arranged, and can show different rows, and every row can show a different number of characters.This device is selected for use and can be shown 2 row, and every row can show the module of 8 characters, and wherein each character uses the pixel of 5 * 7 dot matrix to show.The display module interface circuit is simple, has 8 * 8bit RAM, and working temperature is wide, in 0 ~ 50 ℃ of scope.The LCD video module is made up of liquid crystal board, lcd driver HD44100 and controller.Driver HD44100 is the LCD chip for driving of Low-Power CMOS technology, and it promptly can be worked as row and drive usefulness, also can be used as row and drives use, is made up of 20 * 2bit data latches and 20 * 2bit driver.

Claims (4)

1. the Intelligent Switching Device of analog current and fieldbus signal, it is characterized in that, this Intelligent Switching Device be a kind of be the conversion equipment of WorldFIP fieldbus numeral signal with 4～20mA normalized current conversion of signals, described Intelligent Switching Device comprises modular converter, primary module and display module; Primary module is connected with modular converter, display module respectively, and primary module with traditional analog signal instrument " switching " to the WorldFIP fieldbus.

2. according to the Intelligent Switching Device of described analog current of claim 1 and fieldbus signal, it is characterized in that described primary module comprises microprocessor, communication module and communications interface unit; The address bus A[0:8 of communication module] with data address multiplex bus AD[0:7] be connected the address bus A[0:8 of microprocessor respectively] and D[0:7], and select holding wire ground connection with the microprocessor internal memory chip.

3. according to the Intelligent Switching Device of described analog current of claim 1 and fieldbus signal, it is characterized in that described modular converter comprises that variable connector, signal condition, A/D converter and Signal Spacing constitute.

4. according to the Intelligent Switching Device of described analog current of claim 1 and fieldbus signal, it is characterized in that described display module selects for use character type LCD lattice module to make display device; Its parallel interface is connected with microprocessor bus.

Images