Rabbit Coyote BL2500, Руководство пользователя

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User’s Manual 21
3.3 Digital I/O
3.3.1 Digital Inputs
The Coyote has 16 digital inputs, IN00–IN15. IN00–IN13 and IN15 are each protected
over a range of –36 V to +36 V, and IN14 is protected over a range of –36 V to +5 V. The
inputs are factory-configured to be pulled up to +3.3 V; IN00–IN07 can also be pulled up
to +K or they can be pulled down to 0 V by changing a surface-mounted 0

resistor.
Figure 10 shows a sample digital input circuit. IN00-IN07 and IN15 are protected against
noise spikes by a low-pass filter composed of a 22 k

series resistor and a 10 nF capacitor.
Figure 10. Coyote Digital Inputs [Pulled Up—Factory Default]
Coyote series boards can be made to order in
volume with the digital inputs pulled up to +K or
pulled down to 0 V. Contact your authorized Rab-
bit distributor or your sales representative at for
more information.
The actual switching threshold between a zero
and a one is between 0.9 V and 2.3 V for all 16
inputs.
IN00–IN13 and IN15 are each fully protected
over a range of -36 V to +36 V, and can handle
short spikes of ±40 V. IN14 is protected over a
range of -36 V to +5 V.
Figure 11. Coyote Digital Input
Protected Range
10 nF
22 k W
100 k W
Factory
Default
+3.3 V
GND
0 W
Rabbit 3000™
Microprocessor
R58 R56
+K
R55
+40 V
+36 V
+3.3 V
–40 V
Normal Switching
Levels
Spikes
Digital Input V
oltage
Spikes
Spikes