3. External Connection
42
PIO-64/64L(PCI)H, PI-128L(PCI)H, PO-128L(PCI)H
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
Figure 3.13. Output Circuit < PIO-64/64L(PCI)H >, < PO-128L(PCI)H >
The output circuit of this board is illustrated in Figure 3.13. The signal output section is an opto-
isolated, open-collector output (current sink type). Driving the output section requires an external
power supply.
The rated output current per channel is 100 mA 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 0.5 V or less at an output current within 50 mA or at most 1.0 V at an output current within 100 mA.
To protect against surge voltage, a Zener diode is connected to the output transistor. Also, an
overcurrent protection circuit is attached to a unit of eight output channels.
When the PC is turned on, all output are reset to OFF.
External device
Plus
common
Output pin
Board
External
power supply
12 - 24VDC
Output pin
Vcc
Zener
diode
Zener
diode
Optocoupler
Optocoupler
*
*
Load
Load
Over current protection
CAUTION
