Architectural Overview - Honeywell ISA100 Gen X User Manual

4 Architectural Overview

The architecture of a device conforming to the ISA100 standards is described in terms of the
OSI basic reference model. As shown in Figure 7: ISA100 Device Architecture, each layer
provides a service access point (SAP). The services of a layer are defined as the functions and
capabilities of that layer that are exposed through the SAP to the surrounding layers. The
device manager is the entity within each device that performs the management function.
The ISA100 Gen X Radio Board implements the Device Manager (DMAP), ASLDE0 SAP,
and TDSAP-0 and all the other subsequent layers. The Sensor processor board implements the
User Application Process n (n = 2, 3, 4...15) and the equivalent ASLDE- n SAP and TDSAP-n.
The Sensor board usually contains one user application process. Within the user application
process, you can find one or more transducer blocks, one concentrator block to publish data to
the network, one upload download data object, and one user application process management
object. If the Sensor board implements only one user application process, then the n is usually 2.
The sensor user application process communicates locally to the DMAP present on the Radio
board using reserved local address methods. This includes a local contract id (0) for requests
and reserved destination addresses defined by the Null Address Pointer that is used for the
transfer of local data indications. Confirmation packets are referenced using a request handle
that originates from the requesting data object.
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Release Independent
ISA100 Gen X Radio Module User's Guide
April 2018
Honeywell