CN108259549A - A kind of implementation method of Networked Instrument instrument front-end proxy agent - Google Patents

Abstract

The invention discloses a front-end instrument proxy of networked instruments and a realization method of the proxy of networked instruments and meters. The front-end instrument agent of the networked instrumentation (instrument agent for short) includes: ARM central processing unit, RJ45 wired and Wifi wireless Ethernet interface, USB bus interface, UART/RS232 serial interface, etc. The processor runs the Linux/uCOS operating system, connects to the Internet through the Ethernet interface, connects with the instrument management platform, and accepts its management; connects non-LXI instruments through the USB bus interface and RS232 bus interface, and connects various sensors or control units through other interfaces. The instrument agent supports DHCP protocol, LXI protocol, instrument automatic discovery protocol, SNMP protocol, HiSLIP protocol, and SCPI commands. The instrument management platform can effectively manage the instrument agent and various non-LXI instruments connected to it, various sensors and control units; at the same time, the non-LXI instrument driver can be automatically loaded from the instrument management platform.

Description

A realization method of front-end proxy of networked instrumentation

technical field

The invention belongs to the technical field of network management, and relates to the communication between non-LXI instruments and meters and remote instrument management platforms. The method shields the difference between standard LXI instruments and non-standard LXI instruments, and realizes instrument management through the transfer of instrument agents Unified management of instruments and meters by the platform.

Background technique

In recent years, traditional measurement technology has quietly moved towards networking, and measuring instruments have become the mainstream in measurement and control equipment. In the networked measurement and control system, the data is transmitted to the user terminal through the network, and the user can remotely control the measuring instruments in the system and obtain measurement information without being limited by time and space. Nowadays, most manufacturers directly produce instruments and meters that support the LXI protocol. The LXI (LAN-based Extensions for Instrumentation) bus protocol proposed by the LXI Alliance has laid the foundation for instruments and meters to enter the network era. Instruments and equipment based on the LXI protocol have powerful Network communication function and measurement test function of traditional instruments. However, for the measurement and communication of instruments and equipment, there are still the following deficiencies:

1. At present, most instruments and meters and other measuring equipment are based on USB and RS232 interfaces, and many measuring units are based on bus interfaces such as UART, SPI, CAN, and I2C, as well as ADC/DAC digital-to-analog conversion interfaces, IO control interfaces, etc. It cannot be directly connected via Ethernet to accept the management of the instrument management platform. Therefore, it is of practical significance to convert different types of interface bus devices into unified LXI instruments and equipment, and to realize multi-vendor instruments accepting the management of the instrument management platform.

2. The network in the measurement system and the communication network based on resource sharing have different purposes. The network in the network instrument measurement system usually has to meet the following characteristics: real-time, security, intelligence, reliability and low cost, in order to promote the perfect function of the network measurement system in practical applications, so it is important for the measurement system The network requirements are relatively high. In the network instrument measurement system, intelligence and real-time performance are the main criteria to measure the pros and cons of the measurement and control system.

3. The HiSLIP protocol proposed by the IVI Alliance is based on TCP/IP. The networked measurement system can use the high efficiency, real-time and reliability of the HiSLIP protocol to reduce the impact of sudden abnormal network delays on the measurement and control system. , with the help of the communication channel between the two sides of the HiSLIP protocol, the communication between the networked instruments is realized, so that the instruments work together, and the measurement efficiency of the networked instrument measurement system is improved. In addition, the HiSLIP protocol supports both IPv4 and IPv6, has good backward compatibility, and is more convenient for future networked measurement system expansion. The SNMP simple network management protocol is used for network management. When the instruments and meters are networked, the MIB library in SNMP can also be expanded to be used for the management of instruments and meters in the network.

Contents of the invention

The purpose of the present invention is to fully utilize the advantages of the HiSLIP protocol and the SNMP protocol under the condition of ensuring the real-time and intelligence of the network in the instrument measuring system, and realize the communication between the non-standard LXI instrument and the instrument management platform.

The technical route for realizing the present invention is: introducing an embedded switching device as an instrument proxy, through which non-LXI instrumentation devices with different types of interfaces can be connected to the Ethernet, and the instrument proxy recognizes the standard SCPI commands sent by the instrument management platform, And convert it into commands that can be recognized by non-LXI instruments, and then realize the data interaction between non-LXI instruments and instrument management platforms through the HiSLIP protocol; through the establishment of MIB libraries for non-LXI instruments, the simple gateway protocol SNMP is used to realize the instrument management platform. Management of LXI instruments. The object of the invention is achieved in the following manner:

The communication system between the instrument management platform and non-LXI instruments includes: an instrument management platform (1), multiple instrument agents (2), and multiple managed non-LXI instrumentation devices (24), (25) ,As shown in Figure 1. Each instrument agent is based on ARM processor (4), can run Linux or uC/OS operating system (16), supports TCP/IP protocol (17), supports HiSLIP protocol (18), supports DHCP protocol (19), supports LXI protocol (20), can identify SCPI commands (21), support SNMP protocol (22), support the expansion of MIB library (23), support USB interface (7), RS232 interface (8) types of instruments, support I2C bus interface ( 9), SPI bus interface (10), CAN bus interface (11), UART interface (12), ADC/DAC digital-to-analog conversion interface (13), IO control interface (14) and other interfaces of various sensors, Control unit, as shown in Figure 2. The specific steps to realize the communication between the instrument agent and the instrument management platform are as follows:

1. Support the ARM processor (4) running LinuxOS or uC/OS (16) as the instrument agent (2), the two operating systems support TCP/IP (17), HiSLIP (18), DHCP (19), LXI (20), SCPI (21), SNMP (22) protocols and specific interface data acquisition protocols support common functions driven by interfaces such as Ethernet (5, 6), RS232 (8), and I2C (9). According to different software support levels and different functions, the advantages of each operating system can be maximized. The instrument agent running LinuxOS (16) has drivers for bus interfaces such as USB (7), RS232 (8) and I2C (9). When an instrument of this type of interface is connected to the instrument agent, the instrument agent receives and recognizes the Obtain standard SCPI commands (21) such as instrument configuration, control, and data, and give corresponding response information to the instrument management platform (1); when the instrument agent (2) receives the data request from the instrument management platform, it will use HiSLIP ( 18) The agreement sends the data information required by the instrument management platform to the instrument management platform. An instrument agent running the uC/OS operating system (16), supporting bus interface drivers such as RS232 (8), I2C (9), SPI (10), CAN (11), UART (12), and ADC/DAC digital-analog The drive of interfaces such as the analog-to-digital conversion interface (13) and the IO control interface (14). When the instrumentation of this type of interface is connected to the device, the operation process is the same as that under LinuxOS.

2. In order for the instrument management platform (1) to monitor, analyze, control and manage non-LXI instruments in real time. The SNMP protocol (22) uses objects to represent each managed device resource, and the MIB library (23) is a collection of these objects. According to the configuration information of non-LXI instruments (24) and (25), create a MIB library for adding instruments and meters as the basis for SNMP management of device resources, record the working status of managed resources such as instruments and meters, and achieve efficient instrumentation management.

3. When communicating between the instrument management platform and the instrument agent, the agent supports the DHCP protocol (19), and can obtain the IP address, domain name server and gateway address assigned by the instrument management platform (1); communication between non-LXI instruments and instrument agents At this time, the agent can automatically discover non-LXI instruments by means of polling and monitoring.

4. When communicating between the instrument management platform and the instrument agent, the instrument management platform uses the SNMP protocol (22) to configure the instrument agent, and simultaneously receives alarm information from the instrument agent and non-LXI instrument equipment (24), (25); instrument management The platform is based on the HiSLIP protocol (18) and uses SCPI commands (21) to request data. The instrument agent obtains various measurement data of non-LXI instruments and equipment and transmits them to the instrument management platform through instrument data processing (26) and sensor acquisition and processing (27).

The present invention has the advantage of the present invention compared with prior art:

1. The instrument agent (2) connects to the instrument management platform (1) through Ethernet (5, 6), supports the access of non-LXI instruments (24), (25) and the management of non-LXI instruments.

2. According to different applications, the instrument acts as an agent for two operating system modes: LinuxOS and uC/OS (16). At the same time, hardware platforms that support the corresponding operating systems are selected respectively: Samsung ARM processor S3C6440 development board that supports LinuxOS and uC/OS OS for the NXP LPC1700 development board.

3. The instrument agent realizes the automatic discovery function: the instrument agent and non-LXI instruments are connected to the instrument management platform, and the instrument management platform can be discovered immediately.

4. Dynamic/static IP address allocation function, the instrument agent supports DHCP protocol (19): the agent can automatically obtain the IP address, domain name server and gateway address assigned by the instrument management platform; it can also manually configure the IP address, domain name server and gateway address.

5. The instrument agent supports the SNMP protocol (22) to accept the management of the instrument management platform: non-LXI instruments passively accept the GET/SET command access of the instrument management platform, and support the Trap command to actively send alarm information to the instrument management platform.

6. The instrument agent supports MIB library (23) expansion: the instrument agent constructs the corresponding MIB library according to the interface type of the connected non-LXI instrument, and uses the non-LXI instrument as an SNMP device to accept the management of the instrument management platform.

7. The instrument agent supports the HiSLP protocol (18): through the instrument agent, the non-LXI instrument can be accessed by the instrument management platform, and the data interaction between the instrument management platform and the non-LXI instrument can be realized through the HiSLIP protocol.

8. The instrument agent supports the SCPI specification (21): When the instrument agent connects to non-LXI instruments, it needs to convert standard SCPI commands into commands that can be recognized by non-LXI instruments.

9. The instrument agent supports the access of non-LXI instruments (24), (25): the instrument agent can connect with USB (7), RS232 (8), I2C (9), SPI (10), CAN (11), UART (12) Instrument measurement units with bus interfaces such as ADC/DAC digital-to-analog conversion interfaces (13), IO control interfaces (14), and other interfaces, such as oscilloscopes and digital generators with USB and RS232 interfaces, and I2C , SPI, CAN and other bus interfaces, ADC/DAC digital-to-analog conversion interfaces, and IO control interfaces such as temperature sensor modules, humidity sensor modules, carbon dioxide modules, and lighting modules.

Description of drawings

The present invention can be described and understood in detail with the aid of the accompanying drawings.

Figure 1 is a schematic diagram of the role and status of the instrument agent in the instrument management system;

Figure 2 is a schematic diagram of the composition of instrument agents;

Figure 3 is a schematic diagram of the instrument management system;

Figure 4 is the workflow of establishing a socket link for the instrument agent;

Figure 5 is the instrument management object identifier OID;

Figure 6 is a schematic diagram of the working principle of the instrument agent;

Other aspects and features of the invention will be set forth in the description which follows, or will be apparent from the description, or can be learned by practice of the invention.

Detailed ways

The implementation method of the instrument proxy will be described in detail below with reference to the accompanying drawings. The present invention is shown in Figure 3 in the instrumentation management system.

Multiple instrument agents can be connected via Ethernet, and each instrument agent can be connected to up to 4 non-LXI instruments with various types of interfaces and different functions. The instrument agent supports the DHCP protocol, and can support the IP address, domain name server and gateway address automatically assigned by the instrument management platform. The instrument agent communicates with non-LXI instruments (measurement and control units) through dedicated communication protocols, such as RS232, I2C, USB and other communication protocols. The instrument agent receives the standard SCPI commands sent by the instrument management platform and converts them into commands that can be recognized by non-LXI instruments, and executes corresponding query and control commands. The instrument agent receives the request data command from the instrument management platform, and the instrument agent performs non-LXI instrument data processing and sensor data collection, and then sends the data to the remote instrument management platform through Ethernet, and at the same time, the non-LXI instrument actively sends alarm information and is forwarded by the instrument agent To the instrument management platform, the instrument management platform receives the response information from the instrument agent and processes the alarm information.

The present invention is divided into two types according to the application of the instrument agent: the instrument agent can run under the two operating systems of LinuxOS and uC/OS (16) respectively, and select the ARM processor supporting the corresponding operating system respectively. Samsung S3C6440 processor supporting LinuxOS and NXP LPC1700 series processor supporting uC/OS. Analyzing the characteristics of the two systems, both operating systems support protocols such as TCP/IP, HiSLIP, DHCP, LXI, SCPI, and SNMP, and interfaces such as Ethernet, RS232, I2C bus, and IO. According to different software support levels and different functions under different operating systems, in order to maximize the advantages of each operating system, the following arrangements are made.

When an instrument agent running LinuxOS is connected to an instrument with bus interfaces such as USB, RS232, and I2C, the instrument agent receives and recognizes standard SCPI commands sent by the instrument management platform to acquire configuration, control, and data of the instrument, and the instrument agent converts the SCPI commands into Commands that can be recognized by non-LXI instruments will implement data interaction with the instrument management platform based on the HiSLIP protocol. When an instrument agent running uC/OS is connected to an instrument with bus interfaces such as UART, SPI, I2C, CAN, ADC/DAC conversion interface, and IO control interface, when the instrument of this type of interface is connected to the instrument agent, The operation process is the same as that of the instrument agent running under LinuxOS.

The present invention realizes the method for instrument agency, and the workflow of establishing socket link by the instrument agent is shown in FIG. 4 .

The instrumentation agent (2) needs to communicate with the instrument management platform (1) and interact with non-LXI instruments (24) and (25) at the same time, and there are synchronous channels and asynchronous channels with the instrument management platform. The synchronous channel is used to transmit common control commands and measurement data to the instrumentation, and the asynchronous channel is used to transmit special channels and special states of the instrumentation. There is shared data between the two channels. In order to ensure the reliability of the link, when the instrument agent communicates with the instrument management platform based on the HiSLIP protocol, a set of error handling and locking mechanisms are required to deal with sudden errors and achieve resource security. Sharing, when there is an instrument reading and writing error or reading and writing delay, it is necessary to notify the instrument management platform in time, otherwise the instrument management platform will continue to send commands, resulting in blocking and synchronization errors. At this time, it is necessary to resynchronize the agent and the instrument management platform.

When the instrument agent is initialized, it will create two TCP connections on the same port (4880 by default), one is a synchronous channel and the other is an asynchronous channel. Commands can be sent bidirectionally on the synchronous channel, and the instrument agent packs the data according to the HiSLIP datagram format and hands it to the lower layer TCP (17) for encapsulation, and establishes the socket link of the instrument agent. When the program starts, it will apply for a socket interface and bind the 4880 interface, and then listen to the port. If there is a connection request, it will check whether the maximum number of connections is exceeded. If it exceeds, the request will be rejected, and if there is no connection, the connection will be established. After the connection is established, create a child process to copy the link information of the parent process, and then perform data transmission. The main process will query whether there is a connection request, if there is a connection request, it will close the connection, if not, it will continue to listen to the port.

The invention realizes the instrument agent method, connects the non-LXI instrument, and performs the initialization part of the instrument agent MIB library according to the following steps.

The non-LXI instruments connected in the instrument agent are identified by an object identifier, and the MIB library is a collection of these non-LXI instruments. A MIB library is maintained in each instrument agent to record the working status of the agent's non-LXI instruments. The instrument management platform obtains the usage of system-related equipment by reading the value of the managed object in the MIB, and can also manage and control the system equipment by modifying the value of the managed object in the MIB.

The present invention realizes the method of instrument proxy, and the instrument management object identifier OID of the instrument proxy is as shown in FIG. 5 .

The MIB library of the corresponding instrument is installed on the instrument agent, and the interface type and attribute of the instrument connected to the instrument agent are represented by a unique node (OID number) in the MIB tree. Under the agent of the instrument running the Linux system, according to the interface type of the connected instrument, establish the MIB library of the bus interface such as USB, RS232, I2C, and under the agent of the instrument running the uC/OS system, establish I2C, SPI, CAN, UART The MIB library of bus interface, as well as the MIB library of ADC/DAC conversion interface and IO control interface. In this way, different instrumentation OIDs are assigned to instruments with different interface types and the same function, and instruments with the same interface type and different functions under the agent of the same instrument.

Non-LXI instrumentation OIDs are identified as follows. Since an instrument agent can connect to multiple instrumentation devices at the same time, the following OID is used to distinguish different devices: 1.3.6.1.4.1.1199.x.y. Among them, x represents different instrument interfaces (assuming that one instrument can connect up to 16 instruments or meters), and y represents different types of instruments. According to the IVI specification, the categories of instruments are as follows: 1. Oscilloscope, 2. Arbitrary waveform generator, 3. Multimeter, 4. DC power supply, 5. Switch, 6. Power meter, 7. Counter, 8. Up-converter.

The present invention realizes the method for instrumentation agency, and the working process of the instrument is as follows.

When the instrument is working normally, when the instrument management platform needs to obtain or modify the properties of the instrument, it only needs to send an SNMPGet or SNMPSet message to the instrument agent connected to the instrument, and the instrument agent parses the received SNMPGet or SNMPSet message and finds it in the MIB library. OID, and then send commands that can be recognized by the instrument to modify the specific properties of the instrument represented by the OID. After the agent completes the operation on the instrument, it sends back an SNMP message to the console, and the console completes the entire operation after receiving the message. When the instrument is abnormal, the instrument agent will be notified when the instrument fails, and the instrument agent will send SNMPTrap messages to the console according to the fault type, and the console will make corresponding processing after receiving it.

The present invention realizes the method for instrument agent, and the instrument agent sets instrument parameters according to the following steps.

1. The instrument management platform sends a Set request for setting parameters to the instrument agent through the SNMP protocol, and the process running in the instrument agent receives the setting request.

2. After receiving the setting request, the instrument agent uses a dedicated communication protocol such as RS232 to transmit the setting request to non-LXI instruments. After the non-LXI instrument completes the setup operation, it responds to the instrument agent.

3. The instrument agent responds to the management station with a setting completion message.

The present invention realizes the method for instrument agency, and the instrument agent inquires about instrument information according to the following steps.

1. The instrument management platform runs the instrument management software, sends a Get request for query information to the instrument agent through the SNMP protocol, and the agent process running in the instrument agent receives the query request.

2. The agent reads the information files of non-LXI instruments saved in the instrument agent, and responds to the instrument management platform through the SNMP protocol. In order to ensure the real-time performance of the information stored by the instrument agent, non-LXI instrument equipment periodically (such as 1s) sends its various parameters to the instrument agent through a dedicated interface (such as RS232).

The present invention realizes the method of instrument proxy, and the instrument proxy processes the alarm information of the instrument according to the following steps.

1. When the monitoring program of the instrument agent finds that a non-LXI instrument has an alarm, it will actively send the alarm information to the instrument agent through special interfaces such as USB, RS232, I2C, SPI, CAN, UART, ADC/DAC conversion interface, and IO control interface.

2. When the process running on the instrument agent finds that an instrument has an alarm, it sends the alarm information to the instrument management platform through the SNMP Trap message.

3. After receiving the alarm information sent by the instrument agent, the instrument management platform will deal with it accordingly.

Claims (9)

1. end instrument is acted on behalf of before Networked Instrument instrument（Abbreviation instrument is acted on behalf of）, it is characterised in that：Including arm processor（4）、 RJ45 Ethernet interfaces（5）, wireless WiFi Ethernet interfaces（6）, usb bus interface（7）, RS232 interface（8）, I2C buses connect Mouthful（9）, spi bus interface（10）, CAN interface（11）, UART interface（12）, ADC/DAC digital-to-analogue analog-to-digital conversion interfaces （13）, IO control interfaces（14）Deng；Support Liunx/ μ COS operating systems（16）, support ICP/IP protocol（17）, HiSLIP association View（18）, DHCP protocol（19）, LXI agreements（20）, SCPI orders（21）, snmp protocol（22）, MIB libraries extension（23）, non-LXI Instrument communication agreement（26）, data collection and control processing（27）.

2. the implementation method of Networked Instrument instrument front-end proxy agent, it is characterised in that：Including an instrument management platform（1）, it is more A instrument agency（2）, multiple non-LXI instrumentation devices（24）、（25）.

3. realize that this method step is as follows：

（1）Instrument agency as described in claim 1, which is characterized in that pass through DHCP protocol（19）It is obtained from instrument management platform Dynamic IP addressing, while found instrument agency access automatically or closed by instrument management platform.

4.（2）Instrument agency as described in claim 1, which is characterized in that support snmp protocol（22）And MIB libraries extension（8）, instrument Device management platform（1）As network endpoint monitoring management.

5.（3）Instrument agency as described in claim 1, which is characterized in that support LXI agreements（20）, HiSLIP agreements（18）、 SCPI orders（21）, instrument management platform measures, controls and manages as standard LXI instrument and equipments.

6.（4）Instrument agency as described in claim 1, which is characterized in that there is SCPI instructions（21）With non-LXI instruments（24）、 （25）Conversion function is instructed, runs non-LXI instrument communications agreement（26）, support instrument management platform（1）To non-LXI instruments（24） Observing and controlling.

7.（5）Instrument agency as described in claim 1, which is characterized in that instrument management platform（1）To common interfaces I2C（9）、 SPI（10）、CAN（11）、UART（12）The sensor of interface connection passes through ADC/DAC（13）, I/O interface（14）Carry out mould Analog quantity or switch acquisition/control.

8.（6）Instrument agency as described in claim 1, which is characterized in that when there is non-LXI instrument and meters（24）Access disconnects When, instrument management platform（1）It can find automatically.

9.（7）Instrument agency as described in claim 1, which is characterized in that when finding to there are non-LXI instrument and equipments to access, then open The instrument MIB libraries of dynamic loading network management protocol MIB libraries extension（23）；If there is the driving of correlation type instrument and meter in instrument agency （28）, then into normal operating conditions；When there is no correlation type driving, to instrument management platform（1）Application obtains driving.