Chapter 2 Hardware Overview
© National Instruments Corporation 2-5 NIPCI-1426 User Manual
Note If not configured as single-ended I/O lines, triggers have input only capability.
Wiring an Isolated Input to Output Devices
You can wire an isolated input to both sourcing and sinking output devices.
Refer to Figures2-3 and 2-4 for wiring examples by output type. Refer to
Getting Started with the NI PCI-1426 for information about switching
thresholds and current requirements.
Caution Do not apply a voltage greater than 30 VDC to the isolated inputs. Voltage greater
than 30 VDC may damage the NI 1426.
Note Isolated inputs are compatible with 5 V logic if the external circuit meets the voltage
and current requirements listed in Getting Started with the NI PCI-1426.
Figure 2-3. Example of Connecting an Isolated Input to a Sourcing Output Device
Table 2-1. Trigger Configuration Options for the NI1426
Trigger Number
Single-ended
Input/Output
Alternative
Input Only
0TTL_TRIG(0) ISO_IN(0)
1TTL_TRIG(1) ISO_IN(1)
2TTL_TRIG(2) RS422_IN(0)
3TTL_TRIG(3) RS422_IN(1)
Vcc
Sensor
Power
IN+Current
Limiter
NI 1426
IN–
PNP (Sourcing)
Output Device
Sensor
Common