HOW DOES HSE CONNECT TO H1?
The Fieldbus Foundation (www.fieldbus.org) defines a linking device for this purpose. There are four such types of devices in the specification: • Class 42a is for configuration. It allows TCP/IP client access to extend from the HSE network down to the H1 device and allows the H1 (server) response to travel back up the H1 link to the HSE client. • Class 42b is the same but also transmits events, not just configuration data. • Class 42c is the same as 42b but adds publisher/subscriber messages, which can pass among devices across multiple H1 networks and between H1 and HSE. • Class 42d is the same as 42c but adds extended services for flexible function blocks in H1 devices. Physically, a linking device looks sort of like an Ethernet gateway with multiple channels that manage H1 subnetworks.
