Schneider Electric INTERBUS Basic Network Interface Module What Is a Network Interface Module?

Introduction

What Is a Network Interface Module?

Purpose	An island of STB I/O modules requires a network interface module (NIM) in the
	leftmost location of the basic island. 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
	An island bus is a node of distributed I/O on an open fieldbus network, and the NIM
Network	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, are identical for all NIM
	types.
Communications
Roles	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.
Integrated Power
	The NIM’s built-in 24-to-5 VDC power supply provides logic power to the I/O
Supply	modules on the basic segment of the island bus. The power supply requires a
	24 VDC external power source. It converts the 24 VDC to 5 V of logic power,
	providing 1.2 A of current to the island. Individual STB I/O modules in an island
	segment generally draw a current load of between 50 and 90 mA. (Consult the
	Advantys STB Hardware Components Reference Guide [890 USE 172] for a
	particular module’s specifications.)
	A basic NIM supports up to 12 Advantys STB I/O modules.

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