Understanding The Open Controller Architecture - Allen-Bradley 1747-OC Series User Manual

Understanding the Open
Controller Architecture
open controller
CPU module
to 1746
local I/O bus
Allen-Bradley HMIs
The architecture is basically the same for both open controllers. The
architecture consists of two CPUs (SCANNER and CONTROLLER) that
share dual-port memory. The SCANNER scans the 1746 local I/O bus and
reads/writes inputs and outputs to/from the dual-port registers. The
CONTROLLER has a PC-based architecture with either a 266 MHz
Pentium class CPU or 5x86 class CPU to run your application.
SCANNER
dual-port memory
188
CPU
Partition:
register
bus
commands
responses
memory
output image
input image
host data
SCANNER
software
The dual port is an 8K byte memory partition that provides an interface
between the integrated SCANNER and your application software that
resides on the CONTROLLER. The 1747-OCE open controller uses an ISA
bus interface between the dual-port memory and the CONTROLLER. On
the 1747-OCF open controller, the dual-port memory and CONTROLLER
communicate across a PCI bus.
CONTROLLER (PC-based architecture)
PCI bus (1747-OCF)
266 MHz
ISA bus (1747-OCE)
Pentium
Bytes:
or 5x86
1K
CPU
variable
variable
disk
variable
variable
bus
variable
memory
Introducing the Open Controller
application
BIOS
OS
software
to 1746 PCI bus
1747-UM001A-US-P - March 2000
1-3