Rockwell Automation 5370-CVIM2 Module - Manual (Page 470)

5 Chapter Chapter 9
Discrete I/O Assignments
9–7
Pulse Input Selection: Parts Tracking Function
The pulse input signal enables the CVIM2 system to be synchronized with
the user’s process equipment in order to track parts beyond the physical point
at which the inspections take place –– that is, beyond the camera station.
The pulse input is selected by highlighting “ Toolset n.Pulse ” for the
appropriate toolset ( n ) in the Input Signals panel (refer to Figure 9.3 on
page 9–5). As is the case with trigger signals, you can assign a pulse input
signal to only one discrete I/O input. For example, if you assign
Toolset
1.Pulse to discrete input “ In 0 ,” and then assign that same input signal to
another discrete I/O input, it will be removed from “ In0 .”
In effect, this is a “parts tracking” function that delays the CVIM2 system’s
delivery of “pass/fail” (or other) inspection results to the user’s process
equipment, thereby allowing that equipment to take the appropriate
“accept/reject” action on the inspected parts at a user specified distance
downstream from the camera station.
Since each pulse represents a known distance along a conveyor system, or a
known number of cycles of an indexed machine, the user can specify the
number of pulses that most accurately places the inspected parts within the
accept/reject station. When the CVIM2 system has received the
user–designated number of pulses, it issues the pass/fail results from the
corresponding inspection, and the process equipment can then respond
accordingly at the accept/reject station.
The pulses may originate from a separate encoder device mounted on a
conveyor system. On an indexed machine, the pulse signal may come from
the same trigger signal source that initiated the inspection cycle. The pulse
count parameter (that is, the number of pulses to be counted) can be selected
in the
Delay column of the Discrete I/O Editor panel, after selecting an
appropriate output signal, as illustrated by the examples in Figure 9.6 (A) and
(B) on page 9–11.
To select the pulse count parameter, pick the appropriate box in the Delay
column. When you do, the “calculator pad” appears, as indicated in
Figure 9.4 on page 9–8.
Using the known distance between the camera station and the accept/reject
station, and also the distance that a part travels between successive pulses,
select a pulse count that will ensure the CVIM2 system issues the inspection
results when the inspected parts reach the accept/reject station. For example,
if the distance from the camera station to the accept/reject station were 12
feet (144 inches), and each pulse represented 3 inches, you would need to
select 144
B 3 = 48 pulses.
NOTE: If the trigger signal source is to be used also as the pulse source, the
trigger signal will count as the first pulse count. Thus, if an output is to be set
on the second pulse after the one that initiated the inspection, the pulse delay
count must be set to 3, not 2.