Phidgets 1072, Руководство по эксплуатации продукта

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1072_0_Product_Manual - February 24, 2011 2:52 PM
Digital Inputs
Digital Input Hardware Filter
There is built-in filtering on the digital input, to eliminate false triggering from electrical noise. The digital input is
first RC filtered by a 15K/100nF node, which will reject noise of higher frequency than 1Khz. This filter generally
eliminates the need to shield the digital input from inductive and capacitive coupling likely to occur in wiring
harnesses.
Digital Input Hysteresis
The digital input has hysteresis - that is, it will hold it’s current state (false or true), unless a large change occurs.
To guarantee FALSE, the digital input must be at least 3.75V, and to guarantee TRUE, the digital input must be less
than 1.25V.
Digital Input Sampling Characteristics
The state of the digital inputs are reported back to the PC periodically. During this sampling period, if a digital input
was true for greater than 4.0ms, the digital input is guaranteed to be reported as true in software. This makes the
digital input much more sensitive to reporting TRUE state, and makes it useful to watch for short events. Any Digital
Input True events of less than 1.5ms are never reported.
5Volt Terminal Block
For users who need it, we provide 5V on the terminal block next to Digital Input 7.
Functional Block Diagram
The digital inputs have a built in 15K pull-up resistor. By connecting
external circuitry, and forcing the input to Ground, the Digital Input
in software will read as TRUE. The default state is FALSE - when you
have nothing connected, or your circuitry (switch, etc) is not pulling the
input to ground.
Using the Digital Inputs
Here are some circuit diagrams that illustrate how to connect various devices to the digital inputs on your Phidget.
Wiring a switch to a Digital Input
Closing the switch causes the digital input to report TRUE.
100nF
15K
15K
+5V +5V
INPUT
GROUND
INPUT
GROUND
USER
SW
IT
C
H
W iring a switch to a Digital Input
Phidget
Digital
Input x1
APPLICATION
Monitoring the position of a Relay
K 1
FSR
Isolating a Digital Input w ith an Optocoupler
Phidget
Digital
Input
Closing switch causes digital input to report TRUE Detail of Digital Input
USER
APPLICATION
Relay contact causes Digital Input to report TRUE
Current through LED causes Digital Input to report TRUE
USER
Using an FSR as a switch
APPLICATION
FSR Resistance f alling below 3.75k Ohms causes Digital Input to go TRUE
FSR Resistance rising above 75k Ohms causes Digital Input to go FALSE
This design can be used with any variable resistance sensor - CDS Photocells.
Q1
Detecting an external Voltage with an NPN Transistor
Collector-Emitter Current > 270uA causes Digital Input to report TRUE
Collector-Emitter Current < 67uA guarantees Digital Input to report FALSE
Detecting an external Voltage with an N-Channel MOSFET
1K
R1
Drain-Source Current > 270uA causes Digital Input to report TRUE
Drain-Source Current < 67uA guarantees Digital Input to report TRUE
The resistor on the Gate is not required f or it to f unction, but is a good idea.
Be sure not to exceed VGS of the mosfet.
Drain-Source Current > 270uA causes Digital Input to report TRUE
Drain-Source Current < 67uA guarantees Digital Input to report TRUE
Actual Voltage Required to switch is dependent on VGS required to turn on M OSFET
USER
APPLICATION
USER
APPLICATION
USER
APPLICATION
VS1
10K
R1
VS1
1K
R1
VS1
U1
OptoCoupler
Q1
INPUT
GROUND
Phidget
Digital
Input
INPUT
GROUND
Phidget
Digital
Input
INPUT
GROUND
Phidget
Digital
Input
INPUT
GROUND
Phidget
Digital
Input
INPUT
GROUND
Phidget
Digital
Input
100nF
15K
15K
+5V +5V
INPUT
GROUND
INPUT
GROUND
USER
SW
IT
C
H
W iring a switch to a Digital Input
Phidget
Digital
Input x1
APPLICATION
Monitoring the position of a Relay
K 1
FSR
Isolating a Digital Input w ith an Optocoupler
Phidget
Digital
Input
Closing switch causes digital input to report TRUE Detail of Digital Input
USER
APPLICATION
Relay contact causes Digital Input to report TRUE
Current through LED causes Digital Input to report TRUE
USER
Using an FSR as a switch
APPLICATION
FSR Resistance f alling below 3.75k Ohms causes Digital Input to go TRUE
FSR Resistance rising above 75k Ohms causes Digital Input to go FALSE
This design can be used with any variable resistance sensor - CDS Photocells.
Q1
Detecting an external Voltage with an NPN Transistor
Collector-Emitter Current > 270uA causes Digital Input to report TRUE
Collector-Emitter Current < 67uA guarantees Digital Input to report FALSE
Detecting an external Voltage with an N-Channel MOSFET
1K
R1
Drain-Source Current > 270uA causes Digital Input to report TRUE
Drain-Source Current < 67uA guarantees Digital Input to report TRUE
The resistor on the Gate is not required f or it to f unction, but is a good idea.
Be sure not to exceed VGS of the mosfet.
Drain-Source Current > 270uA causes Digital Input to report TRUE
Drain-Source Current < 67uA guarantees Digital Input to report TRUE
Actual Voltage Required to switch is dependent on VGS required to turn on M OSFET
USER
APPLICATION
USER
APPLICATION
USER
APPLICATION
VS1
10K
R1
VS1
1K
R1
VS1
U1
OptoCoupler
Q1
INPUT
GROUND
Phidget
Digital
Input
INPUT
GROUND
Phidget
Digital
Input
INPUT
GROUND
Phidget
Digital
Input
INPUT
GROUND
Phidget
Digital
Input
INPUT
GROUND
Phidget
Digital
Input