Contec DIO-0808L-PCI, User Manual

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3. External Connection
DIO-0808L-PCI
31
Connecting Output Signals
Connect the output signals to a current-driven controlled device such as a relay or LED.
The connection requires an external power supply to feed currents.
The board controls turning on/off the current-driven controlled device using a digital value.
Output Circuit
Vcc
Zener
diode
Fuse
Board
External circuit
Plus
common
Output
pin
Output
pin
External
power supply
12 - 24VDC
Opto-coupler
Opto-coupler
Zener
diode
Load
Load
Minus
common
* O-xx represents the output pin.
Figure 3.5. Output Circuit
The signal output section is an opto-coupler isolated, open-collector output (current sink type). Driving
the output section requires an external power supply.
The rated output current per channel is 100mA at maximum.
The output section can also be connected to a TTL level input as it uses a low-saturated transistor for
output. The residual voltage (low-level voltage) between the collector and emitter with the output on is
0.5V or less at an output current within 50mA or at most 1.0V at an output current within 100mA.
A zener diode is connected to the output transistor for protection from surge voltages. A Fuse-based
overcurrent protector is provided for every 8 output transistors. When the overcurrent protector works,
the output section of the board is temporarily disabled. If this is the case, turn of the power to the PC and
the external power supply and wait for a few minutes, then turn them on back.
CAUTION
When the PC is turned on, all output are reset to OFF.