Rockwell Automation 1336T Function Block Prog. Manual, Series A/B User Manual
Page 37
2–3
System Component Detail
1336 FORCE — 5.9 August 1995
Within the drive, the execution list is stored as an array of words.
Internally, the execution list for the sawtooth example can be
represented as follows:
Event 1
ID = 01
Type = Limit
010C
Hex Value
0
0
0
0
0
0
0
0
0
Stored in drive
Dec
Hex
=12
=0C
Event 2
ID = 02
Type = SRFF
0216
Dec
Hex
=22
=16
Event 3
ID = 03
Type = Multiplexer
0315
Dec
Hex
=21
=15
Event 4
ID = 04
Type = Ratelim
0413
Dec
Hex
=19
=13
The same execution list using a PLC data table is shown here:
0
1
2
3
4
5
6
7
8
9
N57:0
0000
8F03
4000
0000
0004
0A4A
010C
0216
0315
0413
ID
Type
Event 1
Block Transfer Header Information
Event 2 Event 3
Event 4
Once you complete an execution list, you need to download it to the
drive and compile it to create an application. Only one execution list,
or application, is operating in a drive at any given time.
When the drive enables a function block application, the events are
executed every 20 milliseconds, regardless of how long it actually
takes to execute the application. For example, if it takes the
processor 5 milliseconds to execute your application, the drive’s
processor will not start to execute the application again until the full
20 milliseconds have elapsed. This is referred to as a 20 millisecond
task interval.