Rockwell Automation 5370 CVIM Communications Manual - Manual (Page 28)

Chapter 3
Using Local I/O
3–9
In Figure 3.5, trigger pulse #2 occurs before the CVIM system is finished
processing the inspection cycle started by trigger pulse #1. This causes the
Trigger NAK signal to go high. Trigger NAK will stay high until leading
edge of the next valid trigger pulse (trigger pulse #3).
Figure 3.5
Timing Diagram– Missed Trigger
MODULE
BUSY
* **
Trigger
pulse #1
Trigger
pulse #3
Trigger
(Input)
TRIGGER
NAK
DATA
VALID
Trigger
pulse #2
STROBE
*Min. processing time:
17ms, 256x256 Res.
17ms, 512x256 Res.
34ms, 512x512 Res.
**Analysis time.
TRIGGER NAK goes high because trigger 2 cannot be
processed. (Trigger 1 processing is not yet complete.)
TRIGGER NAK goes low because trigger 3
can be processed. (Trigger 1 processing is
now complete.)
RESULTS Results stay in their current state, hihg or low.