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
