method for monitoring instrumented systems connected to a current loop

Abstract

A method comprising: analyzing at least one instrumented system (102), the analysis of an instrumented system comprising: causing a transmission (200) to the instrumented system of a command according to the HART protocol via a current loop to which the instrumented system is connected; receiving (202) a frame according to the HART protocol transmitted by the instrumented equipment in response to the command, via the current loop; extracting (204) from the frame information indicating whether the instrumented equipment is write-protected; generating (104) a summary message, at least partly in natural language, from each piece of information extracted, the summary message indicating whether or not there are any analyzed instrumented equipment that is not write-protected; and causing a rendering (106) of the summary message to a user by an output device. Figure for the abstract: Fig. 3

Description

Title of the invention: Method for monitoring instrumented systems connected to a current loop FIELD OF INVENTION

[0001] The present invention relates to a method for monitoring instrumented systems connected to a current loop. STATE OF THE ART

[0002] The HART (Highway Address Remote Transducer) protocol was developed in the mid-1980s to enable bidirectional communication of diagnostic and configuration information - in addition to normal process variables - between intelligent field devices and also with a remote equipment management / monitoring system.

[0003] Indeed, it allows both the configuration of connected equipment and the retrieval of operating data provided by the sensors integrated into this field equipment.

[0004] A very large number (around 40 million according to the Fieldbuses Foundation) of sensors, positioners, regulators use the HART protocol for its simplicity and robustness, particularly for equipment located over very long distances, due to the use of a 4 / 20mA current loop.

[0005] The current loop is reliable and highly immune to environmental interference over long communication distances. It is therefore not surprising that it is still widely used in industry today.

[0006] The advantage of the relatively old HART technology is that it is not a totally digital fieldbus, this provides communication security for the analog information that circulates on the 4 / 20mA loop (response from a sensor, control signal, ...) and is difficult to "hack" because the current loop is an analog "point-to-point" link between the instrumentation and a control system.

[0007] The configuration of the sensors via the HART protocol is carried out using question / answer between a master device (computer, tablet) and a slave (instrumented equipment) via "commands" (CMD) which are formatted to respect the structure of the HART communication.

[0008] This therefore makes it a relatively secure protocol if write protection (physical / logical) is active on the instrumented equipment. Write protection can be activated either via switches or in software (activation of a specific command).

[0009] Certain software programs, notably FrameAlyst, which is part of the HART Tools catalog marketed by Borst Automation, can be used to display the "raw" content of response frames provided by instrumented equipment on a screen. A drawback of these programs is that a novice user unfamiliar with the HART protocol is unable to interpret the raw content presented to them. Description of the invention

[0010] One object of the invention is to enable a novice user of the HART protocol to easily identify the existence of unwrite-protected instrumented systems in current loops.

[0011] To this end, a method is proposed comprising: analyzing at least one instrumented system, the analysis of an instrumented system comprising: causing a transmission to the instrumented system of a command according to the HART protocol via a current loop to which the instrumented system is connected, receiving a frame according to the HART protocol transmitted by the instrumented equipment in response to the command, via the current loop, extracting from the frame information indicating whether the instrumented equipment is write-protected; generating a summary message at least partly in natural language from each piece of information extracted, the summary message indicating whether or not there are any analyzed instrumented equipment that is not write-protected; and causing a rendering of the summary message to a user by an output device.

[0012] .

[0013] The method may also include the following optional features, taken alone or in combination whenever technically possible.

[0014] Preferably, the method further includes counting, from each piece of information extracted, a number of instrumented equipment that has been analyzed and is not write-protected, the summary message indicating the number.

[0015] Preferably, the summary message indicates a total number of instrumented equipment that has been analyzed.

[0016] Preferably, several instrumented systems connected to the same current loop are analyzed.

[0017] Preferably, several instrumented systems connected to separate current loops are analyzed.

[0018] Preferably, the output device is a display screen.

[0019] Preferably, the method includes displaying, on the display screen, a progress bar which advances each time an analysis of an instrumented system is performed.

[0020] Preferably, the method further comprises: generating a table indicating for each instrumented system that has been analyzed an identifier or name of the instrumented system and a representative value of the information extracted from the frame emitted by the instrumented system; and causing the table to be displayed on the display screen.

[0021] A second object of this disclosure is a computer program product comprising program code instructions for performing the steps of the above process, when this program is executed by a computer.

[0022] Yet another object of this disclosure is a device comprising: a communication interface for communicating with at least one instrumented system via a current loop; an output device; and a processing module configured to execute the computer program constituting the second object mentioned above. DESCRIPTION OF THE FIGURES

[0023] Other features, objectives and advantages of the invention will become apparent from the following description, which is purely illustrative and not limiting, and which should be read in conjunction with the accompanying drawings on which:

[0024] Fig. 1 schematically illustrates a system according to one embodiment of the invention.

[0025] Figure 2 schematically illustrates a device according to one embodiment of the invention, this device being part of the system represented in [Fig.1].

[0026] The [Fig.3] is a flowchart of steps of a process according to an embodiment, implemented by the aforementioned device.

[0027] Figure 4 is a flowchart of substeps of a scanning step of the process of the [Fig.3].

[0028] Throughout the figures, similar elements bear identical references. DETAILED DESCRIPTION OF THE INVENTION

[0029] With reference to [Fig. 1], a system comprises a device 1 and at least one instrumented system SI, S2, S3 connected to the device via at least one current loop. The equipment communicates with each other using signals conforming to the HART protocol.

[0030] Fig. 1 represents an example in which device 1 is connected to a current loop 2, two instrumented equipment SI, S2 also being connected to this loop; the device is further connected to another instrumented system S3 via another current loop.

[0031] Device 1 is equipment configured to generate commands conforming to the HART protocol and inject them into the current loop 2, these commands being intended to be processed by instrumented equipment.

[0032] Each instrumented device, acting as a slave, is configured to detect and process commands intended for it on the current loop 2. For example, a slave device could be a sensor, a positioner, a controller, etc. Slave devices can typically be used in one of the following applications: petrochemicals, thermal power generation, control of water and / or heat networks, locks, river network systems, etc.

[0033] Each instrumented system has an address on the current loop to which it is connected.

[0034] There are different types of HART commands. For example, some commands are designed to act on an installation (open a valve, change a temperature, modify a configuration parameter, etc.). These commands are called "write" commands because their purpose is to modify the slave's status. Other commands are status commands, instructing a receiving slave to send a response informing the sending master of its internal state. These commands are called "read" commands. Still other commands instruct a slave to update one of its internal parameters (name, password, etc.).

[0035] With reference to [Fig.2], the device 1 comprises a communication interface 6 connectable to one or more current loops 2 and a processing unit 8.

[0036] The communication interface 6 is generally configured to inject HART commands and intercept HART response frames circulating on the current loop 2. The communication interface may include one or more HART modem(s) and a galvanic isolator. The galvanic isolator prevents any risk of unwanted current flow between the current loop 2 and the processing unit 8. It nevertheless allows the transmission of HART signals to and from the current loop 2.

[0037] The processing unit 8 is configured to analyze commands intercepted by the communication interface.

[0038] The processing unit 8 can be of any type: processor, microprocessor, nano-computer (e.g., Raspberry Pi type), programmable or non-programmable circuit (ASIC, FPGA, etc.). The processing unit 8 is, for example, configured to execute a computer program comprising code instructions for this purpose.

[0039] The device 1 also includes a memory 10 capable of storing certain data manipulated or generated by the processing unit 8.

[0040] Device 1 may also include a human / machine interface 12, enabling a user to interact with device 4.

[0041] The human-machine interface 12 includes an output interface for notifying a user of alerts, for example visually and / or audibly. The output interface is typically a display screen, on which certain graphical data can be displayed at the command of the processing unit.

[0042] The human-machine interface 12 further includes an input interface allowing a user to control the operation of the device. The input interface includes, for example, a mouse or a touchscreen. Alternatively or in addition, the input interface includes one or more buttons associated with different actions. The button(s) may be a physical button or a virtual button displayed on a touchscreen.

[0043] With reference to [Fig.3], a method using device 1 comprises the following steps.

[0044] Device 1 is switched on (step 100), for example using a button provided for this purpose.

[0045] In a step 102, the processing module launches a scan of the current loops to which the communication interface 12 is connected. This scan includes N individual analyses of the instrumented system connected to a current loop, with N>1.

[0046] The result of this scan is the acquisition of N pieces of information associated respectively with the N instrumented systems that have been analyzed. Each piece of information indicates whether the associated instrumented system is write-protected or not.

[0047] With reference to [Fig.4], each analysis comprises the following steps.

[0048] In step 200, the processing module 8 requests the communication interface 6 to transmit a command on a current loop to obtain information associated with the instrumented system. The command includes a recipient address on the current loop. This command, conforming to the HART protocol, is known: it is the command called "Command 15 (Read Primary Variable Output Information)".

[0049] The instrumented system located at the address in question receives the command and responds by transmitting a response frame to device 1. The format of this response frame also conforms to the HART protocol. The frame includes the expected information (indicating whether the instrumented system is write-protected or not), but this information is embedded among other data within the frame and is not easily readable. This information is called the Write Protect Code: it is 1 when the instrumented system is write-protected, and 0 otherwise.

[0050] In a step 202, the communication interface 6 receives the frame emitted by the instrumented system.

[0051] In step 204, the processing module 8 extracts the relevant information from the frame. This extraction consists in particular of identifying in the frame the value of the boolean constituting this information (write-protected / not write-protected), which is located at a position in the frame, this position being defined by the HART protocol. Each extracted piece of information is stored in memory 10.

[0052] The preceding steps 200, 202, 204 are repeated for several instrumented system addresses.

[0053] It should be noted that Device 1 may not know the respective addresses of the instrumented systems presented. During the scan, the device can systematically test any address within a predefined address range, i.e., implement step 200 for each of these addresses. Thus, some commands may be sent to addresses not occupied by instrumented systems and remain unanswered. Device 1 is capable of detecting such lack of response within a predefined time.

[0054] During the scan, the processing module causes a progress bar to be displayed on the screen, reflecting the scan's progress. The progress bar advances each time an individual analysis is completed.

[0055] The processing module 8 counts the number M of instrumented systems that have been analyzed and are not write-protected. To do this, the module relies on each piece of information extracted during the scan. This count can be performed by incrementing with a dedicated counter, either during or after the scan.

[0056] The processing module 8 also counts the total number N of instrumented systems analyzed (i.e., those that are actually present). This number corresponds to the actual number of pieces of information received and then extracted.

[0057] Returning to [Fig. 3], in step 104, the processing module 8 generates a summary message, at least partly in natural language, from each piece of information extracted during the scan. The summary message indicates whether or not there are any analyzed instrumented devices that are not write-protected.

[0058] Preferably the summary message indicates the total number of devices analyzed and / or the number of devices that have been analyzed that are not write-protected.

[0059] An example of a summary message in natural language is as follows: "[M] equipment on [N] is not write-protected" (here, [M] and [N] denotes the numeric values ​​of M and N).

[0060] In step 106, the summary message is returned to a user by an output device of device 1. The message may, in particular, be returned visually by the display screen of device 1 and / or audibly by a speaker of device 1. Such a message is very easy for a user to understand, especially a user who is new to the HART protocol.

[0061] Furthermore, in step 108, the processing module generates a table indicating for each instrumented system that has been analyzed: • an identifier or name of the instrumented system (extracted from the frame discussed previously, or from another frame responding to another appropriate command defined by the HART protocol); • a value representing the information extracted from the frame emitted by the instrumented system. For example, this value is 1 when the instrumented system is write-protected, and 0 when it is not; • Optionally, a timestamp indicating the date of analysis of the instrumented system.

[0062] Figure 3 presents this table 108 generation step as being implemented after the scan, but alternatively it can be carried out during the scan.

[0063] In step 110, the processing module 8 causes this table to be displayed on the display screen of device 1. This step is triggered, for example, by a user action, such as pressing a physical button or a virtual button located in a graphical interface also displayed on the screen. This table provides the user with more detailed information than the summary message, if needed.

Claims

Demands

1. A method comprising: • analyzing at least one instrumented system (102), the analysis of an instrumented system comprising: • causing a transmission (200) to the instrumented system of a command according to the HART protocol via a current loop to which the instrumented system is connected, • receiving (202) a frame according to the HART protocol transmitted by the instrumented equipment in response to the command, via the current loop, • extracting (204) from the frame information indicating whether the instrumented equipment is write-protected, • generating (104) a summary message at least partly in natural language from each piece of information extracted, the summary message indicating whether or not there are any analyzed instrumented equipment that is not write-protected, • causing a rendering (106) of the summary message to a user by an output device.

2. A method according to the preceding claim, further comprising counting, from each piece of information extracted, a number of instrumented equipment that has been analyzed and is not write-protected, the summary message indicating the number.

3. A method according to any one of the preceding claims, wherein the summary message indicates a total number of instrumented devices that have been analyzed.

4. A method according to any one of the preceding claims, wherein several instrumented systems connected to the same current loop are analyzed.

5. A method according to any one of the preceding claims, wherein several instrumented systems connected to separate current loops are analyzed.

6. A method according to any one of the preceding claims, wherein the output device is a display screen.

7. A method according to the preceding claim, comprising displaying, on the display screen, a progress bar which advances each time an analysis of an instrumented system is performed.

8. A method according to any one of claims 6 and 7, further comprising • generating (108) a table indicating for each instrumented system that has been analyzed: • an identifier or name of the instrumented system, • a value representative of the information extracted from the frame emitted by the instrumented system, • causing (110) the display of the table on the display screen.

9. Product computer program comprising program code instructions for carrying out the steps of the process according to any one of the preceding claims, when such program is executed by a computer.

10. Device (1) comprising: • a communication interface (6) for communicating with at least one instrumented system via a current loop, • an output device (12), • a processing module (8) configured to execute the computer program according to the preceding claim.

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