CN2733451Y

CN2733451Y - IO analog quantity module for field bus

Info

Publication number: CN2733451Y
Application number: CN 200420023469
Authority: CN
Inventors: 奚培锋
Original assignee: Shanghai Electrical Apparatus Research Institute Group Co Ltd
Current assignee: Shanghai Electrical Apparatus Research Institute Group Co Ltd
Priority date: 2004-06-07
Filing date: 2004-06-07
Publication date: 2005-10-12
Anticipated expiration: 2014-06-07

Abstract

The utility model relates to a Device Net IO analog value module, which belongs to the technical field of field buses. The module comprises an analog value input circuit, a signal amplifying circuit, an AD converting circuit, a single chip computer, a Device Net network, a DA converting circuit and an analog value output circuit. The signal of the circuits is transferred from the analog value input circuit to the signal amplifying circuit, the AD converting circuit, the single chip computer, the Device Net network and the DA converting circuit in turn, so that the signal is amplified, and finally, the analog value is output. The module develops on the basis of a digital value IO module, and a power supply is designed as a switching power supply to reduce the power consumption and realize isolation. The IO analog value module is used for inputting and outputting signals of the analog values of various field devices in industrial control systems, such as sensors, buttons, indicating lamps, valves and transmitters.

Description

A kind of IO analog module that is used for fieldbus

Technical field

The utility model relates to a kind of fieldbus IO module that is used for, and relates to DeviceNet IO analog module or rather.

Background technology

Along with constantly advancing of modernization industry, people have higher requirement to the control of production run.The main flow direction intelligent, networked, that the contemporary automated control technology of decentralized representative develops, and field bus technique impels automated system to comply with the advanced technology of this demand for development just.DeviceNet is based on a kind of open field bus technology of CAN bus, under each big supplier's of the world joint efforts, has become popularity rate than one of higher field bus technique, obtains promotion and application in a big way at home and abroad.

The long-range input/output terminal module of DeviceNet, the various field devices that are used for connecting industrial control system are as the switching value of field devices such as sensor, button, pilot lamp, valve, transmitter and input, the output signal of analog quantity.According to the application scenario of switching value signal, product is divided into switching value input and Switch-Output Type by model; The way of output is divided transistor PNP output, transistor NPN output, relay output type.

Mainly contain the DL205 of U.S. AutomationDirect company abroad by the product of DeviceNet uniformity test, DL105 series, the busstop  series module of American I nterlinkBT LLC, the digital remote IO module of U.S. WAGOCorporation, 1769,1799 modules of U.S. Rockwell Automation, the B-IO module of Germany Benz Co., IO series module of Japan Omron or the like, this module product series that China has only Shanghai Electric Appliances Science Inst (SEARI) design to produce by the IO module of DeviceNet uniformity test at present.

DeviceNet IO module, its principal feature is as follows:

Based on the CAN Physical layer, has powerful communication function; DeviceNet has higher anti-electromagnetic interference capability and communication reliability; The communication speed that can be provided with; Network can be supported 64 nodes at most; Same cable is used in bus power source and communication; Bus is isolated fully with module working power and port power; The accessory power supply power supply is adopted in input, guarantees that bus communication is not subjected to load effect; Modular design, compact conformation, easy to use, cost performance is high; State is shown as control CPU handshaking signal, and display message is accurate; The series module product is by the international DeviceNet consistance of ODVA authentication test.

In general, above-mentioned domestic and international product all reckons without the consistance that product versatility (consistance of product design) and software relate to, and this makes troubles just for product up-gradation, seriation, variation.

Summary of the invention

The purpose of this utility model is to provide a kind of existing product performance that is better than, and considers the fieldbus IO analog module of product versatility, upgrading.

In order to achieve the above object, solution of the present utility model is: hardware of the present utility model is divided into analog quantity input and two modules of analog quantity output, power supply divides three the tunnel, one the tunnel is network electric power, one the tunnel is cpu power, the power supply of control module is provided, and one the tunnel is IO interface module power supply, and the power supply supply of IO interface is provided.The signal transmission of foregoing circuit is: the input of IO analog quantity, successively through signal amplification circuit, analog quantity input change-over circuit, microprocessor CPU, DeviceNet Network Transmission; The output of IO analog quantity is transmitted to microprocessor CPU, digital-to-analog conversion, signal amplification circuit, analog quantity output successively by the DeviceNet transmitted data on network.

The beneficial effects of the utility model: input, output signal in the analog quantity of field devices such as the various field devices that are used for connecting industrial control system such as sensor, button, pilot lamp, valve, transmitter can produce useful effect.

Description of drawings

Fig. 1, Fig. 2 are the theory diagram of IO analog quantity input of the present utility model and output module;

Fig. 3 is host CPU and a peripheral circuit principle schematic among Fig. 1 and Fig. 2;

Fig. 4 is the concrete line principle synoptic diagram of simulated measurement input circuit among Fig. 1;

Fig. 5 is the concrete line principle synoptic diagram of analogue quantity output circuit among Fig. 1.

Embodiment

Below in conjunction with accompanying drawing and a embodiment the utility model is done more detailed explanation than Cui.

With reference to Fig. 1 and 2, this is the block diagram of input and output circuit of the present utility model.

Analog quantity input 1 reaches signal with signal and amplifies 2, through analog to digital conversion 3 differential mode is transferred to common mode, as the input of modulus conversion chip MAX1270, be digital quantity through analog to digital conversion after, import CPU single-chip microcomputer 4 into by the light lotus root.Single-chip microcomputer 4 receives that digital data sends on the DeviceNet network 5.Data transmit-receive on the DeviceNet network 5 adopts the insulation blocking of light lotus root.

With reference to Fig. 3, this is the utility model host CPU circuit.Host CPU described here refers to single-chip microcomputer 4, after receiving data on the DeviceNet network 5, be dealt on the output board by parallel port again, isolate digital-to-analogue chip MAX525 through the light lotus root and receive the data that CPU sends, after converting analog quantity to, after amplifier LM348 amplification, by analog quantity output 7 outputs.

Dial SW is used to measure the switching of electric current and voltage.

The mode that power circuit adopts is the switch vibration that RC adds the field effect pipe, and the input of 24V direct current exports two the tunnel by transformer, isolates fully, and one road 5V is the CPU power supply; Another road is positive and negative 14V, and+14V becomes 5V by 7805, is the input circuit power supply.

Add filtering circuit before the amplifier input of analog quantity load module, parameter is selected accurately can provide measuring accuracy, makes the data of analog-to-digital conversion beat very little.

The output area of analog output module is realized by hardware.

With reference to Fig. 4, this is the schematic diagram of simulated measurement input circuit 1 of the present utility model.It comprises that No. four input circuits, analog to digital conversion circuit, photoelectricity isolates several parts.

With reference to Fig. 5, this is the schematic diagram of analogue quantity output circuit 7 of the present utility model.It comprises that No. four output circuits, D/A converting circuit and light lotus root isolate several parts.

The development of analog quantity IO module is carried out on the basis of digital quantity IO module.Connection terminal based on analog module is few, reduces small product size as far as possible, and the profile of 14 terminal products is adopted in modulus, digital-to-analog conversion.The input of analog quantity IO module, output circuit, the direct supply of the positive and negative 12V of needs.Have improved on other power-supply system: on original DC-DC transformer, increase a winding, three taps, obtained positive and negative 14V power supply by filtering after utilizing self-sustained oscillation, the 5V chip with power supply by 78L05 right+step-down of 14V power supply obtains.

The device that analog quantity IO module adopts is more than digital quantity IO module, requires between each system to isolate each other.

Claims

1. IO analog module that is used for fieldbus, comprise load module and output module, it is characterized in that: described load module also comprises simulated measurement input circuit (1), signal amplification circuit (2), A/D convertor circuit (3), single-chip microcomputer (4) and DeviceNet network (5); Described output module also comprises DeveiceNet network (5) transmission data, single-chip microcomputer (4), DA change-over circuit (6), signal amplification circuit (2), analog quantity output (7); Signal transmission between the foregoing circuit, by above simulated measurement input circuit (1) beginning, be signal amplification circuit (2), A/D convertor circuit (3), single-chip microcomputer (4), DeviceNet network (5), single-chip microcomputer (4), DA change-over circuit (6), signal amplification circuit (2) successively, export to analogue quantity output circuit (7); Power supply is powered to single-chip microcomputer and input, output circuit respectively.

2. IO analog module as claimed in claim 1 is characterized in that: simulated measurement input circuit also comprises No. four input circuits, A/D convertor circuit, photoelectric isolating circuit.

3. IO analog module as claimed in claim 1 is characterized in that: analogue quantity output circuit also comprises No. four output circuits, DA change-over circuit and photoelectric isolating circuit.

4. IO analog module as claimed in claim 1 is characterized in that: described single-chip microcomputer and peripheral circuit thereof also comprise single-chip microcomputer cpu and data transmit-receive circuit.