Clear-Com BAL-8 - Manual (Page 7)

Vitec Group Communications
BAL-8 Ground Isolation Interface Instruction Manual 1 - 1
OPERATION
This chapter describes the BAL-8 Interface and how to operate it.
DESCRIPTION
The BAL-8 provides eight channels of transformer isolation for up to 8
direct interface ports to the Eclipse matrix. The transformer isolation
eliminates the hum and noise caused by ground or earth loops. Each
channel handles four signals (two bi-directional audio and two RS-422
data lines). Only the bi-directional audio lines are transformer isolated;
the RS-422 lines are not isolated.
With the easy-to-operate slide switch, located to the right of each
Input/Output connector pair, you can place each channel in Normal or
Interface mode. In normal mode (Figure 1-1), the data pairs are not
affected. In Interface mode (Figure 1-2), each data pair (i.e., call
receive and call send) is connected, indicating to the Eclipse status
software that the port is in “direct” mode.
Figure 1-1: BAL-8 in Normal Mode (equivalent schematic)
Figure 1-2: BAL-8 in Interface Mode (equivalent schematic)
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