Rockwell Automation 1336T Function Block Prog. Manual, Series A/B - Manual (Page 62)

3–14 System Interactions
1336 FORCE — 5.9 August 1995
To make nodes linked to a common linear parameter operate upon
the same value every 20 milliseconds, you can link the input of the
second event to the input of the first event. As shown here, you could
link the input of event 115 to the input of event 1.
LIMIT
MULTIPLY
Feedback
from the drive
Input
Input
Event 1
Event 115
T1
T2
T1 in this example represents the first transfer of data, and T2
represents the second transfer of data. The data transferred during T2
is the same value that was captured and transferred during T1.
When you create your links, you do not always need to transfer data
from a function block that is executed before the function block that
is receiving the data. For example, if you have a FILTER function
block that has an execution number of 25, the FILTER function block
could receive data from a SCALE function block with an execution
number of 50:
FILTER
SCALE
Drive Parameter
P146
Input
Input
Event 25
Event 50
In this example, you should be aware that even though the FILTER
function block receives data from the SCALE function block, the
drive executes the FILTER function block before the SCALE function
block. The first time the drive executes the FILTER function block, it
uses the input node’s initial or default value because the SCALE
function block has not yet been executed. During subsequent passes,
the FILTER function block always receives the data that the SCALE
function block received during the previous pass. For example, if the
SCALE function block received a value of 56 from the drive during
the fourth time that the drive executes the application, the FILTER
function block will not receive a value of 56 until the fifth time it is
executed.
Link Processing Sequence