Patent Application
20070213042
The domain of the invention is remote control of equipment, and particularly equipment with limited data processing resources. Thus, the invention is applicable for example to remote data recording systems, for example on water, gas or electricity meters, and more generally to telemetry, order monitoring and more generally Machine to Machine (M to M) systems.
Many solutions already exist for performing such operations. They have generally been developed specifically for a given application. In other words, they are “proprietary” solutions that are difficult to adapt to other applications.
There is also a protocol developed by the IBM and ARCOM Control Systems companies (registered trademarks), known as the “MQIsdp Messaging” technology. This technique proposes a communication protocol between one or several items of equipment with limited resources, and one or several servers, using a TCP/IP link.
However, even with this specific protocol, special processing means (microprocessors, memories, etc.) have to be added to the equipment so as to set up a dialog with these remote servers, depending on the required MQIsdp format. The connection between the equipment and the server may use a telephone type link using a modem.
However, in many applications, it would be desirable to be able to manage without a wire telephone link. In this case, radiocommunication means could be envisaged, for example according to the GSM or GPRS standard.
In this case, radiotelephone equipment would be used to perform the modem function. However, according to prior art, it is necessary to associate special and proprietary data processing means with the equipment to set up and exchange data with the server.
This aspect is a very important limitation to the development of the applications mentioned above, and to many other applications with which the MQIsdp protocol could be used.
One particular purpose of the invention is to overcome this disadvantage with prior art.
It should be noted that the fact that this problem has been identified is itself part of the invention. Those skilled in the art are convinced that it is absolutely necessary to equip terminal equipment with sufficient processing means, and will never consider reducing or eliminating these processing means.
However, one purpose of the invention is to simplify the necessary processings in the equipment, and to avoid the need for this equipment to have complex and expensive means such as a microprocessor.
Another purpose of the invention is to propose a simple and generic technique to easily and efficiently set up a dialog with a server using the MQIsdp protocol.
Yet another purpose of the invention is to provide such a technique for setting up a connection between servers and equipment by radiotelephone link in a simple, standardised and inexpensive manner.
Another purpose of the invention is to provide such a technique to develop a large number of applications, without it being necessary to develop specific applications each time.
Another purpose of the invention is to provide such a technique in which there is no need to know the MQIsdp protocol in the developed applications.
Yet another purpose of the invention is to provide such a technique that is technically simple and upgradeable and adaptable to various situations (for example the amount of data to be exchanged) and to any future changes that are made.
These purposes and others that will appear more clearly in the following, are achieved using a system for remote control of equipment enabling interconnection between at least one broker and at least one remote equipment using the MQIsdp protocol.
According to the invention, radiocommunication means capable of sending and receiving AT type commands sent by and/or sent to an external application used by the said remote equipment are associated with at least one of the said remote equipment, the said radiocommunication means being provided with a set of special AT commands for exchanging data with at least one broker using the said MQIsdp protocol, so as to enable an interconnection between the said server(s) and the said remote equipment through the said radiocommunication means, without requiring knowledge of the said MQIsdp protocol in the said remote equipment.
Thus, it is easy and simple to manage data exchanges without the need to develop special applications or to associate important means (particularly microprocessor and memory) with a terminal. Neither the terminal nor the application needs to know the MQIsdp protocol. The radiocommunication means manage these aspects. The application only needs to know the new AT commands according to the invention.
Advantageously, at least in a first mode, the said radiocommunication means only manage signaling of a data exchange, the said data being transferred directly from remote equipment to a server, or vice versa.
Preferably, at least in a second mode, the said radiocommunication means manage signaling of a data exchange and transfer of the said data, the data being temporarily stored in at least one buffer memory.
In this case, the size of the said buffer memory(ies) can advantageously be parameterable.
According to one advantageous embodiment, the said system operates in the said first mode when the size of the said buffer memory(ies) is equal to 0, and otherwise in the said second mode.
Thus, a simple and efficient means is obtained for performing two functions (mode selection and queue sizing) with a single command.
In one advantageous embodiment of the invention, the said radiocommunication means comprise a radiocommunication module comprising all radio frequency and base band processing means on the same substrate, together with means of managing the said AT commands.
In particular, the said radiocommunication means can include the said MQIsdp protocol in the form of an “open-AT” application defining the said set of special AT commands.
Advantageously, the said set of special AT commands includes commands for:
Preferably, at least some of the said special AT commands are organized so as to be able to perform at least two functions and/or to act on at least two distinct aspects, as a function of a predefined configuration.
This can strongly reduce the number of necessary commands, while performing all necessary operations taking account of any future developments.
Thus in one preferred embodiment, the said set of commands only includes 8 commands.
The said set of special AT commands advantageously includes at least one configuration command used to define communication parameters with one of the said servers.
Preferably, the system uses a single configuration command (+WSPGSET) for configuration of radiocommunication aspects and the general configuration of aspects related to the MQIsdp protocol.
In particular, the said configuration command can be used to select one of at least two transmission modes (GSM or GPRS).
Advantageously, the system uses three configuration commands:
Preferably, it also uses at least one general communication command for sending and/or receiving messages using the MQIsdp protocol.
Thus, five general communication commands can advantageously be used:
Advantageously, it also uses at least one query command by an external application, preferably two query commands by an external application, on the following in turn:
The invention also relates to the method for remote control of equipment used by a system as described above. It enables interconnection between at least one server and at least one remote equipment according to the MQIsdp protocol by associating at least one of the said remote items with radiocommunication means capable of sending and receiving AT type commands sent by and/or to be sent to an external application used by the said remote equipment, and by using a set of special AT commands in the said radiocommunication means for exchanging data with at least one server using the said MQIsdp protocol. This enables an interconnection between the said server(s) and the said remote equipment through the said radiocommunication means, without requiring additional processing and/or data formatting means in the said remote equipment.
The invention also relates to radiocommunication devices and modules comprising radiocommunication means used in such an equipment remote control system.
Finally, the invention relates to sets of AT commands used in an equipment remote control system, used to exchange data with at least one server using the said MQIsdp protocol.
Other special features and advantages of the invention will become clearer after reading the following description of a preferred embodiment of the invention, given as a simple illustrative and non-limitative example and appended figures, wherein:
The MQIsdp (WebSphere MQ Integrator SCADA device protocol) is an open standard developed by IBM and Arcom Control Systems (registered trademarks), to enable data exchanges (in the form of messages) from generally inexpensive remote devices (or terminals) with little processing power, to a WebSphere MQ Integrator by TCP/IP server, also called a broker in the following, and vice versa.
MQIsdp (also called Wavecom SCADA in the following) is a data (message) transfer protocol based on a publish/subscribe type communication model freely available on Internet. It may be described as being a simple agnostic data management layer above the TCP/IP protocol, for message management and acknowledgements of reception necessary to assure reliable delivery of the message.
In the publish/subscribe communication model, data are exchanged between a data producer/consumer (the client) and a message broker (the server). The message broker may be considered as being a multi-protocol switching hub for the application protocol that receives the messages, and it transforms them, reformats them, etc. into other structures as a function of a data model defined by the user.
Finally, any transformed messages may be sent (published) by the broker to subscriber clients (zone device, ERP, SAP, Oracle, SQL, etc.) using appropriate client cards. Obviously, the broker can also publish messages that do not originate from a client.
The message broker manages all messages input to and output from an item. A client publishes messages in/with an item or subscribes to messages from/by an item identifying the message flow from the message broker to which or from which the message is to be published.
The MQIsdp specification defines a set of very simple messages including “connect”, “disconnect”, “publish”, “subscribe”, and “unsubscribe”.
2.1 General
Therefore, the invention relates to a new approach for remote control of equipment, particularly based on the use of a set of special AT type commands, enabling an external application to manage data exchanges between a remote terminal and a server, through radiocommunication links (for example a Wismo type (registered trademark) module), without the application knowing the MQIsdp protocol used by the server. This aspect is managed by radiocommunication means, and for example acknowledgements described in the MQIsdp protocol.
According to the invention, the remote terminals (or machines) 11 are associated with radiocommunication means 14, for example in the form of a Wismo module (registered trademark) particularly embedding development tools distributed by the applicant under the “Muse platform” trademark).
2.2 Module Concept
As a reminder, it should be noted that most radiocommunication devices conventionally comprise a set of electronic components arranged on a printed circuit. These various components are designed to perform the various necessary functions, from reception of a RF signal until generation of an audible signal (in the case of a radiotelephone) and vice versa. Some of these functions are analogue and others are digital.
Manufacturing of these radiocommunication devices is an important subject of research. Three objectives are aimed at, that are difficult to reconcile: miniaturising devices, increasing features and simplifying assembly. It is known that installation of different components on a printed circuit is a relatively complex operation, since many components have to be arranged on a very restricted surface area, due to miniaturization requirements.
Therefore, the design of these systems is complex, since it also requires a combination of various components, often from multiple sources, that have to be made to operate together, respecting the specific features of each. Furthermore, after assembling the set of components, calibration and test phases that are frequently long and complex are necessary to guarantee correct operation of the device.
Finally, despite the reduction in size of some components, the assembly occupies a certain surface area that is difficult to reduce.
The holder of this patent application has proposed a method of overcoming some of these disadvantages, consisting of grouping all or at least some of the functions of a digital radiocommunication device in a single module.
Such a module is in the form of a single compact housing, preferably shielded, that device manufacturers can integrate directly without needing to take account of a multitude of components.
This module (also sometimes called a “macro-component”) is actually formed by grouping several components on a substrate, so as to be implanted in the form of a single element. It includes essential components and software necessary for operation of a communication terminal using radio-electrical frequencies. Therefore, there is no longer a set of complex steps for the conceptual design and validation of this terminal. All that is necessary is to reserve the space necessary for the module.
Therefore, such a module can be used to easily and quickly integrate all components into wireless terminals in an optimised manner (portable telephones, modems or any other application using a wireless standard).
Furthermore, since this module contains all essential functions and has been designed as a complete unit, calibration and test problems no longer arise in the same manner, or are at least very much simplified.
Thus, modules distributed by the holder of this patent application are fully tested both in terms of hardware and software on most networks on which they could be used later. Furthermore, the module advantageously encompasses industrial proprietary aspects (since all functions have been grouped together, the module manufacturer manages the corresponding patent right aspects) and technical support aspects.
2.3 AT commands
The principle of using AT commands is already known. For example, it is described in patent document FR-99 13645, and in various specifications distributed by the applicant and that can be referred to for further information if necessary.
2.4 New AT commands
This module 14 is capable of managing a small number of simple AT commands, enabling a simple and efficient dialog with an external application associated with a terminal. It makes the transformation to the MQIsdp format and manages sending and receiving of data 15 using this protocol, in a manner transparent for the application.
Thus, the data exchange can be made using radio waves 16, for example according to the GSM or GPRS standard. Seen from the server 12, information is in the MQIsdp format. There is no need for terminals 11 to know this protocol, they only need to know a few AT commands. It is thus easy and inexpensive to implement an external application at low cost in (or adjacent to) a terminal without the need to provide a microprocessor and memories, and a dedicated application.
As will be seen later, the proposed AT commands may be limited to 8, although they can be upgraded.
Two data transfer modes are proposed:
The first case could correspond to the most frequent case of small messages, and the second case to the transfer of large files, as is allowed for in the MQIsdp protocol. It is thus possible to manage everything through the module, without adding any external memory and intelligence, while enabling data transfers with a volume greater than the storage capacity of the module.
Advantageously, a single command can be used for sizing of buffers and changing from one mode to the other (the second mode corresponding to a zero value).
Such a module 14 usually comprises:
According to the invention, a library 26 of special commands (Wavecom SCADA Protocol Library) is provided to communicate using the MQIsdp protocol that is above the TCP/IP library 24.
The AT commands 27 address either the base layer 21, the TCP/IP library 24 or the SCADA library 26 depending on the case.
The proposed interface using AT commands includes only 8 commands in this library 26, capable of fully controlling the MQIsdp protocol and particularly:
The following describes AT commands that could be used to control the Wavecom SCADA protocol 26.
3.1 Related documents
If necessary, the following documents provide useful information:
[1] This document should be read with the “WebSphere MQ Integrator SCADA Device Protocol” datasheet given in Appendix B of the “IBM WebSphere MQ Integrator Programming Guide” reference manual available at the following address:
http://publifp.boulder.ibm.com/epubs/odf/bipval04.pdf
[2] Wavecom AT Commands Interface Guide
Reference: WM_SW_OAT_IFS—001- revision: 009 or more recent versions.
This document describes AT commands managed by the Wavecom product to manage related GSM events or services.
[3] AT Command Interface for TCP/IP
Revision: 1.7
This document describes the parameters and the set of AT commands for configuration and control of superposition of TCP/IP and protocols available on Wavecom products.
3.2 Abbreviations And Definitions
3.2.1 Abbreviations
APN Access Point Name
AT: Attention
DNS Domain Name System
ISP Internet Service Provider
ME Mobile Equipment
SCADA Supervisory Control and Data Acquisition
MS Mobile Station
QoS Quality of Service
Wavecom core software:
Software layer managing all AT commands so that related GSM events or services can be managed.
3.2.2 Definitions
The terms MS and ME are used for mobile terminals handling GSM services. The word “product” refers to any Wavecom product (particularly a module) handling the AT commands interface.
Symbols:
<CR> carriage return character
<LP> line feed character
[ . . . ] optional parameter of an AT command
< . . . > Parameter name between angle brackets. The angle brackets do not appear on the command line.
3.3 AT Command Syntax
This section defines the format of AT commands, and mechanisms for assignment of default values of their parameters.
3.3.1 Command Line
Commands always begin with the standard “AT+WSP” prefix and finish with the <CR> character.
Optional parameters are indicated between square brackets [].
For example: AT+WSPCmd=<Param1>[,<Param2>]
In this example, <Param2> is optional. When the AT+WSPCmd command is executed without <Param2>, the default value of the <Param2> parameter is used.
3.3.2 Information Responses And Result Codes
Responses begin and end with <CR> <LF> (except for the format of the ATVO DCE response) and ATQ1 commands (deletion of result code) (see the related document [2]).
3.4 Configuration Commands
Different parameters are necessary to provide the Wavecom product with all information about the initial connection:
3.4.1 +WSPGSET General Parameters
a—Description
This command is used to configure all parameters used to select the support network, the different timeouts and the functional mode of the Wavecom SCADA protocol.
b—Syntax
c—Defined Values
d—Possible Error Codes
e—Informative Examples
3.4.2 Connection Parameters +WSPCSET
a—Description
This command is used to configure all connection parameters (by family).
b—Syntax
c—Defined Values
d—Possible Error Codes
e—Informative Examples
3.4.3 Parameters For the Will+WSPWMS Message
a—Description
This command configures all parameters related to the Will message. This command returns +WSP ERROR: 4013 if the value 0 is assigned to the <OutBoxSize> parameter.
b—Syntax
c—Defined Values
d—Possible Error Codes
e—Informative Examples
Note:
if the <ctrl>P command is present in the text, the <ctrl>P <ctrl>P escape command will have to be used.
3.5—General Commands
5 3.5.1—Definition of the WSP+WSPDCONT Context
a—Description
This command defines parameter values for a WSP context identified by the local context identification parameter <WSPCid>.
A maximum of two WSP contexts can be defined.
A special form of the defined command, +WSPDCONT=<WSPCid>, is used to delete a WSP context.
b—Syntax
c—Defined Values
d—possible error codes
+WSP ERROR 4000 Non-activated function of the Wavecom SCADA protocol. This error is returned when the function of the Wavecom SCADA protcol has not been activated in the WISMO module.
+WSP ERROR 4001 Illegal operation. This error is returned when an incorrect parameter is detected.
e—Informative Examples
3.5.2 +WSPCONM Connection Management
a—Description
This command manages the connection to a broker.
b—Syntax
c—Defined Values
d—Possible Error Codes
e—Informative Examples
3.5.3—Send Message+WSPSMSG
a—Description
This command sends or obtains the status of several message types, and particularly Publish, Subscribe and Unsubscribe.
The specification of the Wavecom SCADA protocol enables a SUBSCRIBE/UNSUBSCRIBE message to send several subscriptions/unsubscriptions. The limit for this AT command is fixed at one item per SUBSCRIBE/UNSUBSCRIBE message. In this case, an application that wants to subscribe/unsubscribe from several items will send several SUBSCRIBE/UNSUBSCRIBE requests for a single item.
b—Syntax
c—Defined Values
(*) Maximum length of the message body. This value is limited by the value of the <OutBoxSize> parameter. If the value 0 is assigned to the <OutBoxSize> parameter, there is no limit (see the +WSPGSET command section for further information about the <OutBoxSize> parameter).
Note:
if MsgType = 10 (UNSUBSCRIBE), then only the <Topic> parameter is compulsory.
Else, if MsgType=8 (SUBSCRIBE) then
Else, if MsgType=3 (PUBLISH) then
Then, assign the number of bytes indicated by the <PayLoadLength> parameter to the <Payload> parameter.
Or
d—Possible error codes
e—Informative Examples
Notes:
[1] If there is a <Ctrl>P in the text, the <Ctrl>P <Ctrl>P escape command has to be used.
[2] The <MsgHandle> parameter is only managed if the value 32767 bytes is assigned to the <OutBoxSize> parameter (see the General parameters section, +WSPGSET command).
When the value 0 is assigned to the <OutBoxSize> parameter, the <MsgHandle> parameter is set equal to the value 1 each time.
3.5.4- Reception of the +WSPRMSG Message
a—Description
This command is used to read a received message. The message is received with the +WSPIMSG indication.
The broker can send a PUBLISH message to the client on any item to which the client is subscribed. This AT command is used to obtain messages arrived in the InBox queue.
This AT command is only available if the value 0 is not assigned to the <InboxSize> parameter (see general parameters, +WSPGSET command). If the value 0 is assigned to the <InboxSize> parameter, messages are displayed with the +WSPIRMSG indication.
b—Syntax
c—Defined Values
d—Possible Error Codes
e—Informative Examples
3.5.5 +WSPPA Protocol Administration
a—Description
This command makes a general reset in the various queues or restores the default values of all parameters.
b—Syntax
c—Defined Values
d—Possible Error Codes
e—Informative Examples
3.6 WSP Indications
This chapter describes all event responses for sent messages.
3.6.1 +WSPDCONI Connection Indications
A connection indication mechanism (+WSPCONI) is set up so that the external application can determine the connection status.
These indications are sent when a value between 1 and 3 is assigned to the <NotifyLevel> parameter (see the +WSPGSET command).
3.6.2 +WSPSMSGI Message Send Indications
A (+WSPSMSGI) message indications mechanism is set up so that the external application can determine if the message is received or if a message has been sent.
These indications are sent when the value 2 or 3 is assigned to the <NotifyLevel> parameter (see the +WSPGSET command) and if the value 32767 is assigned to the <InboxSize> parameter.
3.6.3 +WSPRMSGI Message Reception Indications
If the Inbox size (<InboxSize>) is zero (0), messages are displayed with the +WSPRMSGI indication as soon as they are received.
These indications are sent when the value 2 or 3 is assigned to the <NotifyLevel> parameter (see +WSPGSET command) and when the value 0 is assigned to the <InboxSize> parameter.
The message header and/or the payload are displayed as a function of the +WSPGSET RecMsgMode parameter.
3.7 Error Codes
This chapter describes all error codes returned by WSP AT commands.
This section gives examples of the use of all AT commands in the Wavecom SCADA protocol described above. These examples are shown in
In these figures, the information is presented using a format well known to those skilled in the art, clearly showing data exchanges between the various entities (server or broker, module and external application). The fourth column shows which commands are used, and their meaning when applicable.
It does not seem necessary to add further comments on these figures, those skilled in the art will be capable of interpreting them directly.
The following aspects are presented:
4.1 Receiving a message with OoS 0
4.2 Receiving a message with OoS 1
4.3 Receiving a message with OoS 2
4.4 Sending a message with QoS 0
4.5 Sending a message with QoS 1
4.6 Sending a message with OoS 2
4.7 Comments
In these various figures, it can be seen that the external application does not need to know the MQISdp protocol (PUBLISH, PUBREC, PUBREL, PUBCOM commands, etc.), all it needs to know are the AT commands described above.
The module makes the interface transparently. Programming of the module to make this interface is obvious, firstly from the specifications given above, and secondly from the specifications for the MQIsdp protocol.
| Number | Date | Country | Kind |
|---|---|---|---|
| 03/07244 | Jun 2003 | FR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/FR04/01499 | 6/16/2004 | WO | 9/7/2006 |
