I saw a news alert, New technical guide available for using WirelessHART devices in industrial applications, which pointed to a detailed document, System Engineering Guidelines IEC 62591 WirelessHART. I’ll highlight a few items from this document.
Part I from the guide looks at the use of WirelessHART technology in project execution from the Appraise (conceptual design) stage through to the Pre FEED (Front End Engineering and Design), FEED, Execute and Operation stages.
Part II looks closely at the field network components that comprise these wireless networks.
The guide opens with some definitions and acronyms. For example, a Join Key is defined:
A 128 bit security key used to authenticate wireless field devices when joining the network, including encryption of the join request.
A common Join Key may be used among all devices on a given network, or each device may have a unique join key.
Note: When displayed in hexadecimal format via a browser or handheld, this results in a 32 character hexadecimal field.
The guide includes 13 sections:
- Project Concepts
- Front End Engineering Design
- Project Management
- Field Device Requirements
- Ancillary WirelessHART Devices
- Measurements and Choosing WirelessHART Devices
- Host System Requirements
- Documenting in Intergraph SPI 2009
Additional there are four appendices:
- Example ISA Specifications
- Design Resources
- Wireless Spectrum Governance
Organized around the lifecycle of a project, the guide provides insights into the questions that should be addressed in each phase. For example, during the pre-feed phase, guidance is provided on selecting the right technology based on the type of control or monitoring application:
Another example is guidance for WirelessHART security in the Execute phase of a project:
When designing networks, every Gateway and thus every network must have a unique Network ID. Wireless device Join Keys may be configured as either common per Gateway or individual/unique per field device. If common Device Join Keys are selected as the option, each field device will share the same Device Join Key. If individual Join Keys are selected, each field device in the network will have a unique Join Key.
Individual Join Keys provide stronger security and are recommended. Even with common Join Keys, it is recommended practice to use different values for each Gateway and network.
The Join Key is the most important parameter for implementing security. Users can know the Gateway HART tag and the Network ID for the network that the Gateway manages, but a wireless field device cannot join the network without a Join Key. The design engineer should be sensitive to the security policies of the design firm and the security policies of the future owner-operator and, as a minimum, treat the Join Key with the same sensitivities as a password for a server to a DCS or database. For this reason, storing the join key as a field in a design database is not prudent.
As with all your automation, instrumentation and network equipment, security to prevent physical access to this equipment is a critical part of your site security processes.
The wireless specialists that developed this guide invite you to share any feedback you may have about the guide.
You can also connect and interact with other wireless experts in the Wireless group in the Emerson Exchange 365 community.