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An
optional plug-in board provides an isolated three-state, parallel, stored
Binary Coded Decimal (BCD) output to external devices such as PLC's,
panel-mount printers, and dataloggers. The output rate can be either
continuous or programmable (to accommodate printers that print at
programmed time intervals).
Signal
levels are LPTTL- and CMOS-compatible (selectable for 5 or 15 VDC
logic). Isolated power for the BCD outputs is provided by an
on-board supply, to ensure freedom from ground loops.
BCD
connections are via a 30-pin 0.1" mass termination ribbon cable
connector on the rear on the BCD output board.
BCD
outputs of multiple meters—as in the second figure below—can be
multiplexed by addressing each meter with its own "Enable"
line. Only the addressed meter will provide data output, while the
other non-addressed meters are held in a non-transmitting, high-impedance
output state. "BCD Hold" and "Data Ready"
outputs further simplify the interface.
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Parallel
BCD Communications |
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|
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Multiplexing
of Multiple BCD Outputs
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| BCD
Output Specifications
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Power
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Provided
by basic meter
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|
Type |
3-state, stored,
parallel, isolated |
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Signal
Levels |
LPTTL-, CMOS-compatible |
|
Controls |
BCD Enable, BCD
Hold, Data Ready |
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Isolation
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Safety-rated
to 250 VAC, 4.2 kV peak per high-voltage test
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