Control Engineering asks Sierra Wireless about industrial networks, AirVantage

Sierra Wireless launched the AirVantage Smart Automation, an extension to the company’s AirVantage cloud platform for machine-to-machine (M2M) applications. Control Engineering asked additional questions about automation, comparisons with other industrial network options, integration, and security.

01/31/2011


Sierra Wireless AirLink Fastrack Xtend EDGE programmable gateway offers quad-band EDGE connectivity in a ruggedized, plug-and-play form factor.About today's launch of Sierra Wireless AirVantage Smart Automation, an extension to the company’s AirVantage cloud platform for machine-to-machine (M2M) applications, Control Engineering asked additional questions about automation, comparisons with other industrial network options, integration, and security. Brian Anderson, vice president of marketing for AirVantage at Sierra Wireless, provided answers. Here's the Q&A.

Question 1. How does this differ from what currently is available?

Current systems collect data from the control system busses (modbus, etc.), and pass that data directly up to the server application (HMI, Historian, etc.), they have simple configuration to select which name/value pairs to read off the control bus, and can send the data as it arrives or collect the data locally and send all the data at a particular time.  We call these systems “always connected, data pass through” systems.

Smart Automation: In addition to the above capability, the application developer has much more control of the data collected from the control system. For example, Instead of sending all the temperature readings from the control system business logic can be employed to only send temperature readings if it exceeds a threshold. Systems with PLC’s could apply similar logic to the PLC and the system could read that name-value pair threshold achievement, but separation of application logic from control logic allows the control system to be consistent across the machines they are controlling, and the application developer create the client-server application required for that particular end customers service requirements.

Sierra Wireless on Jan. 5, 2011, announced availability of the AirPrime MC7750 embedded wireless module, designed to connect to the Verizon Wireless 4G LTE Mobile Broadband network and can be integrated into a variety of devices.Smart Automation is a 2-way communications system, so an HMI application may be able to control a remote machine, for example reset a machine. This requires integration with the control system logic.

Q2. How or in what circumstances would this be better than other networking options and how?

Smart Automation provides for Business Logic in the communications device (Sierra Wireless AirLink, Sierra Wireless AirPrime, or third-party device), separating the control system logic from the business logic (embedded application logic). This is beneficial because control systems can be maintained to the machine model and version, making a more reliable control system, and the same model and version may have widely different applications due to the requirements of the end customer with that particular machine. Also the application developer has the ability to securely push new business logic to the communications device, without affecting the operation of the control system.

In addition to the above, AirVantage Operating Portal offers all the cloud services require to develop, deploy and operate an M2M system.

Q3. How does the smart automation extension integrate with industrial control systems? (physical layer and software?)

RS-485, RS-232, and Ethernet are the physical layers for various software, network protocols: Modbus RTU, Modbus ASCII, Modbus TCP, and Modbus Plus (Modbus+, MB+ or MBP). There is a roadmap to support other Control bus standards, like DNP3.

Q4. Is this Sierra Wireless AirVantage Smart Automation announcement a device and a service?

AirVantage Smart Automation is an M2M cloud platform offered as a service to M2M application developers to make M2M Applications. Smart Automation makes it easier to connect industrial control systems and manipulate the data at the client, so it consumes less network and server bandwidth. It works on Sierra Wireless AirPrime and Sierra Wireless AirLink devices which are integrated into the control system.

Q5. What about security?

All data transferred to and from the control system uses a protocol over http or https (customer can decide), the latter being SSL encrypted. All code (Business logic, Software, and Firmware) being sent to the communications device leverages the OMA-DM standard (used for Firmware-Over-The-Air (FOTA) at most Mobile Network Operators to update cell phone applications and firmware). The OMA-DM standard calls for MD5 or HMAC-MD5 authentication, we have implemented the HMAC version, which adds payload integrity checking to the MD5 system. In addition to HMAC-MD5, each update package (group of Business logic, Software, and Firmware) is PKI signed by the AirVantage server before being sent to each registered client, the client will compare its unique key with the key the server sent and only open and install the update package if the keys match. This eliminates rogue servers attempting to update code in wireless devices. For more about the OMA-DM specification, please refer to section 5 to 5.4 of this PDF: http://www.openmobilealliance.org/Technical/release_program/docs/copyrightclick.aspx?pck=DM&file=V1_2_1-20080617-A/OMA-TS-DM_Security-V1_2_1-20080617-A.pdf

See more on wireless networks from Control Engineering:

- Mark T. Hoske, CFE Media, Control Engineering, www.controleng.com



No comments