VX4101A MultiPaq Instrument User Manual 2–33
Using the Digital Input
This section includes guidelines and procedures for the following operations of
the Digital Input:
HProgram the Digital Input
HRead the current input
HRead points using external handshake
What You Should Know About
Upon start-up, all Digital Input pins are active.
Since both the Digital Input and Output share the same pins, the Digital Input
detects any voltage applied to the Digital Output. The 32 pins of the Digital
Input physically share the same pins with the Digital Output. If you are using
both the Digital Input and Digital Output, each common pin will be set to low if
either the Digital Output or your connection to the Digital Input drives it low.
If the Digital Output source is external and no external voltage is applied, the
Digital Input level of unconnected Digital inputs will be affected by other
connected Digital Inputs.
Pin Usage for Only the Digital Input. If you are not using the Digital Output, then
you should select one of the following internal excitation values:
H5 VDC
H12 VDC
H24 VDC
Select the level based on whether the measured inputs are nominal 5 VDC or
less, 12 VDC or less, or higher than 12 VDC.
You can program the Digital Input to trigger as follows:
HNormal triggers
HOn a pattern

Start-Up

Shared Pin Assignments

with Digital Output

Digital Output Source

About Triggering