Contec DIO-24DY-USB, User Manual

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3. External Connection
22
DIO-24DY-USB
Connecting I/O Signals
As I/O signals are LVTTL (3.3V) level signals, the total cable length should be within 1.5 m.
The input is provided with an input protective resistor (33
Ω
).
GND is common to all I/O pins.
Figure 3.5. Input Circuit
Figure 3.6. Output Circuit
If the signal source is affected by noise or distant from the product, the product may fail to input accurate
data depending on the connection.
I/O signals are LVTTL-level active high signals. When the external input signal is LVTTL level, the
Low level represents logic 0 and the High level represents logic 1. When the program outputs 0 and 1,
the product outputs the Low and High level signals, respectively.