YSI WaterLog Series, Руководство пользователя

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Digital In
The Digital I/O Ports are located on the lower first block of the front panel. The first port of the
block is the Digital ground (Dgnd). As Inputs, the digital signal has an internal pull up resistor of
47K Ohms. This allows a switch closure to ground to activate the input. It can also be driven
using normal logic levels.
Port(s): Defines which port is currently being measured and will be used as the Task Value.
Mode: Defines the current mode of the Digital Input. Digital Inputs have four modes of
operation: Level, Frequency, Event Counter, and Quad Counter. Level and Event Counter
Modes allow the Edge Triggered (Event-driven)Type to be used.
Level
The default mode for a Digital Input is Level. This Digital Value gives the current state of the
digital I/O pin. As an Input, the value will be a 1 or a 0 meaning “On” or “Off” respectively. If
the pin value is a 1, the input voltage will be approximately 3.5 volts or higher, (normally 5.0
volts). If the pin value is a 0, the input voltage will be approximately 0.8 volts or less, (normally
0.0 volts). The range between 0.8 and 3.5 is not defined and may be either a 1 or a 0.
This Mode could be used to test the status of an external device, such as a motor. The digital I/O
pin would be used as the source for data; a 1 would be measured if the motor was on, a 0 would
be measured if the motor was off.
System 5000
Inputs 5-7
TM