Rockwell Automation 5370-CUPK Color CVIM USER-PAK Option - Manual (Page 57)

Chapter 6
Creating Custom Serial Port Messages
6 – 8
Figure 6.7 The Buffer box
Buffer box
Picking the Buffer box toggles the setting between Buffer: Wait and Buffer:
No wait.
Buffer: Wait
The two Buffer box settings are described below:
•
Buffer: Wait – With Buffer: Wait selected, the Color CVIM transmits
your custom serial port messages with priority over inspection triggers.
That is, if one or more inspection triggers are received while the Color
CVIM is waiting to transfer a serial port message to the buffer, the
received triggers are rejected while the Color CVIM completes the
message transmission. This is a concern mainly if the trigger rate is fast
enough, and the serial message transmissions are long enough, to cause
triggers to be rejected.
Note: When a trigger is rejected, the Trigger Missed bit is set, and the
missed trigger count is incremented. (see the chapter on remote I/O in the
Color CVIM Communications Manual for more information on discrete
bits).
An advantage to selecting Buffer: Wait is that the serial messages can be
as lengthy as the time between triggers permits, and as lengthy as Color
CVIM memory allows. A disadvantage is the possibility that, in some
cases, some triggers may not be processed.
Buffer: No wait
•
Buffer: No wait – This is the default setting. With Buffer: No wait
selected, the processing of inspection triggers has priority over the serial
port message transmissions.