Rockwell Automation 57C650 AutoMax Programming Executive Version 3.8 - Manual (Page 27)

2Ć5 Introduction to the AutoMax Distributed Control System
Drive Control
Tasks that control Distributed Power Drives (DPS) are stored and
executed on UDC (Universal Drive Controller) modules in the rack.
UDC tasks are written in control block language. They are referred to
as UDC tasks." See the appropriate DPS programming and
configuration instruction manual for more information about UDC
tasks.
MultiĆTasking
AutoMax Processors are capable of multiĆtasking. Each AutoMax
Processor can execute multiple application tasks based on a priority
basis, sharing common data between tasks. Application task
execution can also be coordinated using BASIC language statements
and functions in both BASIC and Control Block tasks.
Each UDC module can execute two independent Control Block tasks
to control two separate drives of any type, usually referred to as
Drive A and Drive B. UDC tasks A and B execute sequentially (task A
executes, then B) based on a userĆdefined interval of 500 msec CCLK
signal. If only one task is required, i.e., the UDC module will control
only one drive, the drive can be connected through either channel A
or B.
The UDC tasks on one module share the data in the dual port
memory. UDC tasks cannot, however, share data with tasks on other
UDC modules, or with tasks on AutoMax Processors, unless an
AutoMax task reads from or writes to the UDC's dual port memory.
Only AutoMax tasks can move data between two or more UDC tasks
on different UDCs, and between UDC tasks and AutoMax tasks.
The following table illustrates the differences between UDC modules
and AutoMax Processors.
UDC Module and AutoMax Processor Comparison
Maximum #
in a Rack
Maximum #
of Tasks** Programming Languages
AutoMax
Processor
4 32
BASIC, Control Block* or
PC/Ladder Logic
UDC Module 10
2 (1 each for
drives A/B)
Control Block*
ă* A subset of BASIC statements and functions is permitted. The two types of
Control Block tasks (UDC and AutoMax) support slightly different subsets.
These are listed in the Control Block instruction manual (JĆ3676) and in
Appendix C of this manual.)
** Each rack can have a maximum of 32 tasks loaded into it. This total does not
include BASIC include" tasks.