- Field device—Routing
- Field device—Non-Routing
- Backbone Router
- System Manager
- Security Manager
The architecture of an ISA100.11a system is flexible, allowing various network topologies to be formed by combining the various functional entities listed above, based upon the application requirements. The Nivis ISA100.11a System incorporates firmware, hardware and software for all its functional entities, thus providing a comprehensive solution.
Field devices form wireless packets coined as DLL subnets. Depending on the application and the available network backbone infrastructure, there are two major network topologies: ISA100.11a network with no backbone and ISA100.11a network with backbone.
ISA100.11a Network with No Backbone
This topology addresses customer needs for smaller deployments. It concentrates all wireless field devices into a single DLL subnet that communicates directly with the gateway and the System/Security Manager without relaying the packets over an infrastructure backbone. This topology allows for reduced communication latencies as well as better predictability of network behavior.
ISA100.11a Network with Backbone
When deployments stretch over a larger geographical area such as interconnected halls within a plant, the favored topology is an ISA100.11a network that connects multiple DLL subnets through a network backbone. This topology facilitates extension of the ISA100.11a network, both geographically as well as in terms of number of devices.
The DLL subnet ends at the Backbone Router, which provides a communication link between the wireless field devices and the backbone infrastructure. The technology employed in the backbone is not mandated by the ISA100.11a workgroup. Both wireless and wired backbones are viable options.