WO2014202664A1

WO2014202664A1 - Network commissioning and control system and method

Info

Publication number: WO2014202664A1
Application number: PCT/EP2014/062821
Authority: WO
Inventors: Mallikarjun Kande; Ravish Kumar; Apala Ray
Original assignee: Abb Technology Ag
Priority date: 2013-06-21
Filing date: 2014-06-18
Publication date: 2014-12-24

Abstract

Network commissioning and control system and method for evaluating and/or controlling the resource utilization in an industrial wireless sensor network comprising one or more field devices and/or operator portals and/or wireless network management components including one or more executable data structures and processing units such as network manager, security manager, access points, gateways, performs and executes the steps of: f. accumulating the network operational parameters; g. analyzing the network resource utilization; h. analyzing the field device resource utilization; i. comparing with pre-set threshold parameters; j. finding out over-loaded network or field device.

Description

Network commissioning and control system and method

Description

The invention relates to a network commissioning and control system and method as well as a process automation system with such commissioning and control system for the commissioning and adaptive planning, structuring or design of a data or information network, in particular a sensor network, of a process automation system.

Generally in a plant automation system or a process automation system comprising a DCS (Distributed Control System) field devices are connected with the DCS via a gateway directly or through access points and one field device should be connected to solely one access point or gateway. There is no way or possibility in which a field device can be guided and/or "switched" so that it chooses a Network Access Point which for example is having lesser load/connection to handle and/or a higher "network or signal quality". Moreover, during run-time the access points can be overloaded when many field devices join these points based on their high signal strength. Based on high signal strength the respective device cannot decide and/or distinguish whether a network is loaded or not and accordingly whether the expected perfor- mance can be achieved or not.

Therefore the object of this invention is to provide a more efficient possibility or way of guiding and/or advicing a new field device to join in a preferred network in an process automation system .

This is achieved by a process automation system according to features of claim 1 . Further advantageous embodiments and refinements as well as a corresponding method are disclosed in further claims and the following description. The network commissioning and control system and method for evaluating and/or controlling the resource utilization in an industrial wireless sensor network comprising one or more field devices and/or operator portals and/or wireless network management components including one or more executable data structures and processing units such as network manager, security manager, access points, gateways, performs and executed the steps of a. accumulating the network operational parameters; b. analyzing the network resource utilization; c. analyzing the field device resource utilization; d. comparing with pre-set threshold parameters; e. finding out over-loaded network or field device.

Accordingly the invention relates to a process automation system comprising at least one data processing unit and an analyzing unit for analyzing and/or controlling re- source utilization of each field device and access points or gateways to determine the "best" gateway or access point to join the network and to achieve and ensure a maximized data and network quality and/or data transmission quality.

In a further embodiment means are provided for adding the resource analysis in gateway or central node, where the respective device is applied and/or resides in each field device.

The assignment of a field device to a gateway/ access points is generally done mostly based on the network quality and communication aspects like signal strength, dis- tance from gateway or access points. Therefore, the coverage of the gateway/ access points is important factor, whereas a gateway/ access point typically provides one network so a field device must be provisioned with the correct unique network ID to be able to communicate. For that, it is required to assess the joining network. The QoS (Quality of Service), for example signal strength may show high if the devices are close to one network but it does not guarantee the good performance if the network is over-loaded.

So, it is a challenge to determine which network a device should join during provi- sioning.

During run-time of the network, it might happen that a network is getting over-loaded with lots of packet transfer. Though all the devices during engineering have joined in suboptimal network, the network characteristics may change while operational. A particular field device can be configured to send more data if the application is critical. In another scenario, a particular device is routing more packets which may reduce the life-span of the battery.

So, it is a challenge to determine when a device should be moved between networks.

In a further embodiment the process automation system comprises at least one wireless communication and/or sensor network, in particular at least one WirelessHART network, which is already deployed in the industrial plant and considering the large plant area there might be more than one network and/or more than one network type.

In case an additional new device is required to be put inside the plant, it is required to know at which network this new device is required to be commissioned. Based on the signal strength, it is not possible to decide and /or select the adequate or optimal network as the network which is showing comparatively higher signal strength might be over-loaded.

To overcome this situation, an analyzing unit is provided, in particular comprising executable program code means, for example a software module or data structure or computer program product, in at least one gateway/ access point which analyzes the resource utilization in the network by monitoring at least one of the packet transfer, battery consumption, signal strength etc., in particular for a respective gateway and/or field device. In a further refinement a network manager and/or a network management device is provided comprising and/or containing all the network related information accessibly stored at a data storage and/or a database, so that said information can be request- ed and/or retrieved , in particular by at least one of a manual request, on a cyclic basis, automatically and continuously, from the network manager and/ or the network management device.

Based on the provided data and the performed analysis, the analyzing unit suggests whether one access point/gateway is or may be over-loaded or whether the new field device will have better coverage if it is connected to a different network, for example Network#2 instead of Network#1 .

In a further refinement this analyzing unit may also be integrated in or applied to a DMS/DCS or Commissioning Tool like in particular a handheld.

Based on the dynamic changes in wireless environment, the network characteristic may differ which might affect the QoS of the network. Moreover, there might be additional traffic through a particular node which can affect the coverage in the network. In all these cases, the operator needs to know whether some device is required to be moved from one network and how to decide which device is required to be moved.

Furthermore the analyzing unit evaluates and determines which network is less loaded and determines by removing of which field device from over-loaded network this over-loaded network will become "normal" and normal loaded respectively. Based on this result, the particular device is chosen to move or to be removed from the overloaded network to a different less-loaded or normal network.

In one embodiment the analyzing unit, in particular for adaptive planning purposes, monitors the traffic in the network with their source address. Based on threshold parameters, it evaluates if any particular node is creating over-load in the network and it evaluates if such a high amount of data is expected from that particular device. If a discrepancy is determined at least one alarm device is activated and an alarm signal is generated or initiated and/or an alarm message is sent to an operator. In a further embodiment the analyzing unit for adaptive planning is built as a standalone device or may be integrated in a DMS/DCS or realized as part of a commissioning tool like in particular a handheld or mobile device. It must be interfaced with the network manager of the network, so that it can access all the necessary information of network, which are needed for further processing.

The further disclosure and explanation of the invention as well as advantageous embodiments and further developments are presented according to at least one illustrative embodiment.

Fig 1 discloses a process automation system comprising at least one network commissioning and control system executing the corresponding method, wherein an analysing unit is provided comprising executable program code means to perform a workflow based on the respective method for the commissioning and adaptive planning and control of the wireless network of a process automation system and in particular the network structure and arrangement of said process automation system.

After starting the workflow in a first step 10, stepwise the network data and infor- mation, in particular the network operational parameters, will be accumulated and gathered 20. In a second step 22 the network resource utilization will be analyzed and determined and the results will be compared with pre-set threshold parameters 24 to determine an overloaded network and/or field device. If the result of the comparison shows that no threshold has been exceeded the network resource utilization will be analyzed again (back to step two 22). If the threshold parameters are exceeded 26 in a next step 30 the resource utilization of each field device will be analyzed and in a further step 40 the results will be compared with pre-set threshold parameters. If the threshold parameters are exceeded a list of overloaded devices is generated and/or the respective devices are marked as overloaded 60 and the system evaluates if such a high amount of data is expected from that particular node and/or device. If a discrepancy 70 is determined in a further step 80 at least one alarm device is activated and an alarm signal is generated or initiated and/or an alarm message is sent to an operator and/or the workflow ends. If no discrepancy is detected the workflow restarts in step 2 and once again the network resource utilization is analyzed.

In a further embodiment, in case a discrepancy is detected and an alarm is generat- ed, the workflow may be restarted automatically in step 1 or step 2 to verify and to check the former results.

According to the disclosed method as well as the performed workflow described above the analyzing unit will measure and/or determine the load' of each network device, for example like an access point based on the resource utilization of network devices like access points and the number of Field devices being handled by the network devices like access points.

The analyzing unit may be integrated or may be part of any of the provided network devices of the process automation network, in particular a wirelessHART network, of the process automation system, and may be integrated or part of each of the provided network managers or the network management system.

The analyzing unit in the respective network devices is cooperating and/or communicating with the analyzing unit in the respective network manager and is regularly updating the analyzing unit in the respective network manager with regard to their re- source utilization, evaluating and determining which network is less loaded and determining by removing of which field device from over-loaded network this overloaded network will become "normal" and normal loaded respectively.

Based on this result, the particular device is chosen to move or to be removed from the over-loaded network to a different less-loaded or normal network.

The analyzing unit determines the traffic in the network at a specific location and/or a specific network or source address, wherein based on threshold parameters, the unit evaluates if any particular node and/or device is creating over-load in the network and furthermore evaluates if such a high amount of data is expected from that partic- ular node and/or device. If a discrepancy is determined in a further step at least one alarm device is activated and an alarm signal is generated or initiated and/or an alarm message is sent to an operator. Furthermore, the analyzing unit is built as a stand-alone device or may be integrated in a DMS/DCS or realized as part of a commissioning tool like in particular a handheld or mobile device. It must be interfaced with the network manager of the network, so that it can access all the necessary information of network, which are needed for further processing.

The analyzing unit terms and/or marks the network devices 'overloaded' based on a threshold value wherein o Initially, the software module puts a minimum value as the threshold value. In particular the threshold value is a dynamic and relative value which can vary from network device to network device. o Later gradually based upon the network condition (for example, network device like access point resource utilization, and number of field devices connected through an access point, number of access points available) this threshold value will be changed dynamically. o The algorithm for calculation of the threshold value will take into account the load of the neighboring network devices. o The threshold value calculating algorithm will take care of the computation of load threshold value. o The analyzing unit in access point will maintain a list of network devices like access points vs. threshold value. This list will be updated periodically.

The respective analyzing unit in the network manager or the network management system will o Suggest to 'Reject' new join request from the field devices through the overloaded network devices like access point. o It will then see availability of under-loaded network devices like access point and the field device will be allowed to 'join' through that network devices like access point. In case a network device like access point crosses or exceeds a threshold due to its resource utilization, then analyzing unit will suggest a field device to rejoin through another network device like access point and the parameters will be commissioned. The Network commissioning and control system, in particular the analysing units in the respective devices and the network manager or network management system, and method, in particular in adaptive planning, monitors and/or controls the traffic in the network with their source address. Based on threshold parameters, it evaluates if any particular node is creating over-load in the network and it evaluates if such a high amount of data is expected from that particular device. If it finds a discrepancy, it raises am alarm to the operator.

An exemplary embodiment of a process automation system comprising three networks (network 1 , network 2 and network3), each network comprising an access point 1 ,2,3 and several nodes Nodes 1 ...Node 24. The analyzing unit formed or built as a software module for adaptive planning can be working as stand-alone or integrated with DMS/DCS or commissioning tool like Handheld. It must be interfaced with the network manager of the network where it can have all the necessary information of network. According to the embodiment of Fig. 2 the Process portal of the process automation system as well as several nodes of each network comprise the analyzing unit according to the invention, wherein the analyzing unit is built and/or realized as a software module.

The following section presents an example of the functionality of the software module

• The software module will monitor the network condition such as at least one of memory or processing load, RF power, remaining battery life, num- ber of field devices being handled by the network devices, number of paths it is covering to reach master node or gateway, receiver signal strength information for each network devices.

• Based on above information, the software module will analyze the load' of the network device which is handling a number of field devices. · The software module will compare the load' with a threshold value. This threshold value is a relative and dynamic number which can vary between network devices. The threshold value calculating algorithm will take care of the computation of load threshold value.

• The software module will define the network devices 'overloaded' when the monitored load' crosses the threshold value. · The network management component will maintain a list of network devices like access points vs. threshold value and the list will be updated based on the input from software module.

• The software module will guide the network management component to reject the join request in an overloaded network and guide the new device to join in an under-loaded network.

• During operational phase of the network, the software module will guide network management to ask field device from an overloaded network to join an under-loaded network. This scenario more or less assumes that a WirelessHART network is already deployed in the industrial plant and considering the large plant area, it might have more than one network (in the example of Fig. 2 three networks).

When an additional new device is required to be put inside the plant, it is required to know at which network (network 1 ... network 3) this new device is required to be commissioned. Based on the signal strength, it is not possible to decide the network as the network which is showing comparatively higher signal strength might be overloaded. To overcome this situation a network commissioning and control system with at least one analyzing unit, realized as a software module, in gateway/ access points is provided, which analyzes the resource utilization in the network by monitoring the packet transfer, battery consumption, signal strength etc for the gateway and the field device.

This information can be retrieved from the network manager which ideally has and is aware of all the network related information. Based on this analysis, the system suggests whether one access point/gateway is over-loaded or the new field device will have better coverage if it is connected to Network#2, instead of Network#1 .

This software module can also be integrated with DMS/DCS or Commissioning Tool like Handheld.

Based on the dynamic changes in wireless environment, the network characteristic may differ which might affect the QoS (Quality of Service) of the network. Moreover, there might be additional traffic through a particular node which can affect the coverage in the network. In all these cases, the operator needs to know whether some de- vice is required to be moved from one network and how to decide which device is required to be moved.

For that the software module analyzes the resource utilization of the network and as well as each field devices.

Now, the respective software module evaluates which network is less loaded and removing of which field device from over-loaded network, makes this network as normal. Based on this result, the particular device is chosen to move from overloaded network.

The software module in Adaptive Planning monitors the traffic in the network with their source address. Based on threshold parameters, it evaluates if any particular node is creating over-load in the network and it evaluates if such a high amount of data is expected from that particular device. If it finds a discrepancy, it raises am alarm to the operator.

Claims

1 . Network commissioning and control method for evaluating the resource utilization in an industrial wireless sensor network comprising one or more field devices and/or operator portals and/or wireless network management components including one or more executable data structures and processing units such as network manager, security manager, access points, gateways, wherein the steps of a. accumulating the network operational parameters; b. analyzing the network resource utilization; c. analyzing the field device resource utilization; d. comparing with pre-set threshold parameters; e. finding out over-loaded network or field device are being performed.

2. Method as claimed in claim 1 , characterized in that the load in the respective network and field device is detected and/or determined.

3. Method as claimed in claims 1 or 2, characterized in that it may be applied to any of the network devices and/or gateway or access points as well as network managers.

4. Method as claimed in one of the preceding claims, characterized in that the network devices overloaded will be termed based on a threshold value where the threshold value is dynamic and relative value.

5. Method as claimed in one of the preceding claims, characterized in that the load threshold will be varied depending upon the network condition like availability of network devices.

6. Method according to one of the preceding claims, characterized in that it is used to guide a new device when more than one network is available in the plant.

7. Method according to one of the preceding claims, characterized in that it is performable even when the network is not working as expected and/or the device is commissioned for sub-optimal network

8. Method according to one of the preceding claims, characterized in that an alarm is raised when flooding attack is detected.

9. Network commissioning and control system for evaluating the resource utilization in an industrial wireless sensor network comprising at least one data processing unit and one or more field devices and/or operator portals and/or wireless network management components including one or more executable data structures and processing units such as network manager, security manager, access points, gateways, which system a. accumulates network operational parameters; b. analyzes network resource utilization; c. analyzes field device resource utilization; d. compares the retrieved information and data with pre-set threshold parameters; e. determines and identifies over-loaded network or field devices.

10. System as claimed in claim 9, characterized in that the load in the respective network and field device is detected and/or determined.

1 1 . System as claimed in claims 9 or 10, characterized in that it is used at least for one of any of the network devices and/or gateway or access points as well as network managers.

12. System as claimed in one of the claims 9 to 1 1 , characterized in that network devices are termed 'overloaded' based on a threshold value, wherein the threshold value is dynamic and relative value.

13. . System according to one of the proceeding claims 9 to 12, characterized in that an alarm signal is raised and/or warning note is sent when flooding attack is detected.