Considerations When Connecting The Digital I/O; Wiring An Isolated Input To A Sourcing Output Device - National Instruments NI PCI-8254R User Manual

Chapter 2 Digital I/O

Considerations When Connecting the Digital I/O

Wiring an Isolated Input to a Sourcing Output Device

Caution Do not apply a voltage greater than 30 VDC to the isolated inputs. Doing so could
damage the NI 8254R.
NI PCI-8254R User Manual
The isolated trigger inputs on the NI 8254R are current sinking and
optically isolated. The following are considerations you need to make when
connecting the digital I/O.
You can wire an isolated input to a sourcing output device, as shown in the
following figure. Refer to the NI PCI-8254R Quick Start Guide for
switching thresholds and current requirements.
The following figure shows an example of connecting an isolated input to
a sourcing output device.
Sourcing
Output
Device
V
Input
Current
Limiter
C
NI 8254R
2-12
Vcc
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