DFI302
Foundation Fieldbus^TM Universal Bridge

DFI302 has a large variety of system components for the applications, it includes:

	Controllers		Power supplies and power supply impedances
	I/O modules		Barriers
	Interfaces		Repeaters
	Powe Supply		Accessories
	Overview

DF49/53
Power Supply Impedance for Fieldbus

These modules were specially designed to provide ideal impedance for fieldbus networks. The only difference between them is the quantity of fieldbus ports supported:

• DF49 (2 ports)
• DF53 (4 ports)

The impedance function is to implement an output circuit which impedance is greater than 3 KW and in parallel with two terminators of 100W ±2% each, results in line impedance of about 50W. This impedance can be implemented in a passive mode (50 resistance in series with a 100 mH inductance) or in an active mode, through an impedance control circuit.

The fieldbus power supply impedance is a non-isolated, active impedance control device, in accordance with Standard IEC1158-2. This device presents output impedance which, in parallel with the two bus terminators (a 100 W resistor in series with a 1 mF capacitor) required by the standard, results in a purely resistive line impedance for a broad frequency range. The DF49/DF53 cannot be used directly in areas requiring intrinsic safety specifications.

Some Characteristics: