GE GFK0579B Parts of a Remote Drop, Multiple Racks, Distance Between Racks in a Remote Drop

1

Parts of a Remote Drop

Together, a Remote I/O Scanner and the modules it serves make up a remote drop on the Genius bus. The remote drop may consist of one to eight Series 90±70 racks.

REMOTE DROP

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RACK 0

PS B S C T A M

N N E R

RACK 1

PB S R M

RACK 6

PB S R M

RACK 7

PB R M

GENIUS BUS

UP TO 50 FEET

NOTE: ALL RACKS MUST BE AT THE SAME GROUND POTENTIAL

Multiple Racks

When there are multiple racks, the Remote I/O Scanner must be located in the first rack (rack 0). To link multiple racks in a remote drop, a Bus Transmitter (IC697BEM713) Module in rack 0 is connected to a Bus Receiver Module (IC697BEM711) in the first expansion rack. Additional racks are also linked via Bus Receiver Modules.

All racks in a remote drop must be at the same ground potential.

Distance Between Racks in a Remote Drop

The maximum total cable length from the first Bus Transmitter to the last Bus Receiver in a remote drop is 50 feet (15 meters). Since none of the daisy±chained signals (all at the same ground potential) are broken at a rack, any rack can be independently powered±down without affecting the operation of the rest of the system.

Data Quantities

Regardless of the number of racks used for a remote drop, the maximum amount of data for a remote drop is 128 bytes of inputs and 128 bytes of outputs (8 discrete points represent one byte and 1 analog channel uses 2 bytes).

Chapter 1 Introduction 5