Schneider Electric 890USE17700 - Manual (Page 12)

Introduction
12 890USE17700 April 2004
What Is a Network Interface Module?
Purpose Every island requires a network interface module (NIM) in the leftmost location of the
primary segment. Physically, the NIM is the first (leftmost) module on the island bus.
Functionally, it is the gateway to the island bus—all communications to and from the
island bus pass through the NIM. The NIM also has an integrated power supply that
provides logic power to the island modules.
The Fieldbus
Network An island bus is a node of distributed I/O on an open fieldbus network, and the NIM
is the island’s interface to that network. The NIM supports data transfers over the
fieldbus network between the island and the fieldbus master.
The physical design of the NIM makes it compatible with both an Advantys STB
island and your specific fieldbus master. Whereas the fieldbus connector on each
NIM type may differ, the location on the module front panel is essentially the same.
Other NIM connectors, such as the power supply interface and the CFG interface
(See The CFG Interface, p. 33), are identical for all NIM types.
Communications
Roles Communications capabilities provided on a standard NM include:
Function Role
data exchange The NIM manages the exchange of input and output data
between the island and the fieldbus master. Input data, stored in
native island bus format, is converted to a fieldbus-specific
format that can be read by the fieldbus master. Output data
written to the NIM by the master is sent across the island bus to
update the output modules and is automatically reformatted.
configuration services Custom services can be performed by the Advantys
configuration software. These services include changing the
operating parameters of the I/O modules, fine-tuning island bus
performance, and configuring reflex actions. The Advantys
configuration software runs on a computer attached to the NIM’s
CFG port.
human-machine interface
(HMI) operations An HMI panel can be configured as an input and/or output
device on the island bus. As an input device, it can write data
that can be received by the fieldbus master; as an output device,
it can receive updated data from the fieldbus master. The HMI
can also monitor island status, data, and diagnostic information.
The HMI panel must be attached to the NIM’s CFG port.