GE Fanuc Bus Interface Unit Power Supply

Profibus Bus Interface Unit

The Profibus Bus Interface Unit is a small, rugged, intelligent module with a sturdy

aluminum housing. The module has three status LEDs and a connector for a Hand-held

Programmer.

The Bus Interface Unit requires an external source of 24 VDC power.

The BIU's internal power supply provides power for the operation of the BIU itself, and

logic power for the I/O modules connected to it.

It mounts on a separate terminal block, to which it and all field wiring are attached. The

configuration is stored in non-volatile memory located in the terminal block.

The Bus Interface Unit has a replaceable 1A, 5x20mm 250VAC slow-blow fuse on the

input power lines. The fuse can be changed without disturbing the wiring of any other

modules.

Bus Interface Unit Power Supply

The 24 VDC power supply in the Bus Interface Unit provides power for the Bus

Interface Unit itself and logic power for all I/O modules that may potentially be installed

at that station. External power must be supplied for field wiring of input and output

devices. Specifications for the BIU power supply are listed on page 1-11.

The BIU power supply is not damaged by either of the following:

Reversing input voltage on terminals 1 and 2.

Temporary overcurrent conditions on the 6.5 VDC output.

Timing

The Bus Interface Unit provides power to all I/O modules that are installed at the station.

I/O module operation is governed by a System Reset signal to ensure controlled

operation during the power up and shut down processes. As shown in the timing

diagram below, momentary power losses of less than 10 milliseconds do not affect I/O

module operation; however, longer power losses generate a Reset for all system I/O

modules.