National Instruments NI CVS-1450 Series - Manual (Page 56)

Chapter 4 Digital I/O Functionality
NI CVS-1450 Series User Manual 4-8 ni.com
Table 4-3 lists the product selection ports.
General-Purpose I/O
General-purpose inputs and outputs are available as both TTL and isolated
connections. At any time, the software running on the CVS-1450 device
can read the inputs and drive the outputs high or low.
General-Purpose Inputs
The primary difference between general-purpose inputs and trigger inputs
is that you cannot use general-purpose inputs to initiate a timed pulse
generator. In an application, use the general-purpose inputs to get the status
of the inputs at a given point and not to synchronize the CVS-1450 device
with an external event.
An example of how to use general-purpose inputs is reading the status of
a general-purpose input as the first step in your inspection sequence and
recording that value as part of your inspection.
General-Purpose Outputs
The primary difference between general-purpose outputs and timed pulse
outputs is that the timing of general-purpose outputs is controlled by
software rather than hardware. As a result, timing of general-purpose
outputs changes as the inspection algorithm changes, which makes
general-purpose outputs less appropriate than timed outputs for camera
control, strobe light control, and other applications that require precise
timing.
Table 4-3. Product Selection Port
Function External Connection
Data(5), rising edge latch ISO Input 5
Data(4) ISO Input 4
Data(3) ISO Input 3
Data(2) ISO Input 2
Data(1) ISO Input 1
Data(0) ISO Input 0