Shared Channels; Dip Switch Settings - Geokon 8800-2-1A Instruction Manual

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3.4 Shared Channels

Some Geokon instruments utilize multiple gages that share a single conductor for negative
polarity. During normal operation, each channel of the Multiplexer consists of four signals,
which are all switched together: VW+, VW-, TH+, and TH-. However, the Multiplexer can be
configured to switch the VW- signal separately from the rest, allowing for configurations where
multiple gages share one common VW- signal. This shared conductor may be connected to the
VW- on any of the channels to which the various gages have been wired.
Switching of the VW- signal is controlled by an eight-position DIP switch located on the left side
the circuit board. This DIP switch tells the Multiplexer which channels are sharing a common
VW- signal. Use the table located on the top left corner of the circuit board (reproduced in Figure
15) to determine which of the eight switches to move to the on position based upon which
channels are sharing a common VW- signal.
For example: If the VW+ conductors of a four gage load cell were wired into channels four, five,
six, and seven, then the common conductor for these gages may be wired into the VW- of any of
those four channels. Consequently, switches four, five, and six on the eight-position DIP switch
would be moved to the ON position.
Figure 15 - DIP Switch Settings