Rockwell Automation SA3100 Distributed Power System Drv Config,Program - Manual (Page 88)

3-50 SA3100 Drive Configuration and Programming
3.6 Application Registers (Registers 300-599, Every
Scan) (Registers 1300-1599, Every Nth Scan)
The application registers are used to pass application-specific data between the
AutoMax Processor and the UDC module.
Memory is allocated for a maximum of 600 application registers. There are 300
registers that can be used every scan (registers 300-599) and 300 registers that can
be used every Nth scan (registers 1300-1599). “N” is defined in register 2001. Note
that the status of application registers is not retained after a STOP ALL.
Application registers 300-599 can be used every scan of UDC tasks. Registers within
this range written to by a UDC task are updated by the UDC operating system from its
local memory to dual port memory after each task is run. Registers within this range
written to by an AutoMax task are read by the UDC operating system from dual port
memory and copied into the UDC local memory at the beginning of each scan in order
to have a consistent context for evaluation. See figure 3.1.
Note that the same bits or registers must not be written to (and used as outputs)
by both an AutoMax task and a UDC task.
Application registers 1300-1599 can be used every Nth scan of the UDC task. Nth
scan registers should be used when it is necessary to synchronize one or more UDC
tasks to an AutoMax task.
The registers within this range (1300-1599) that are written to by a UDC task are
updated by the UDC operating system from its local memory to dual port memory at
the end of the scan that occurs before the Nth scan (N-1). At that time, an interrupt will
be generated by the UDC operating system to indicate that new data has been written
to the dual port memory. Refer to the 2000-series registers for more information on
interrupts. An AutoMax task must have defined a hardware EVENT in order to be able
Figure 3.1 – UDC Task Scan
Input A Run A Output A Input B Run B Output B
UDC Scan*
Feedba
ck From
PM
I
Co
m
m
and t
o
PM
I
*Task B can act on Task A outputs within a scan.
Latch “every scan”
registers that are
inputs to task B
Write “every scan”
registers that are
outputs from task A
Latch “every scan”
registers that are
inputs to task A
Write “every scan”
registers that are
outputs from task B