Configuration of Instrumentation System
Section
1-2
34
The following CPU Unit Terminal function blocks are used:
Number of points
Function block
128 contacts
DI Terminal from CPU Unit (Block Model 451)
Input
64 contacts
DI Terminal from Expanded CPU Unit (Block Model 455)
128 contacts
DO Terminal to CPU Unit (Block Model 452)
Output
64 contacts
DO Terminal from Expanded CPU Unit (Block Model 456)
Note 1
In addition to the above number of points, the CPU Unit Terminal block differs
from the Expanded CPU Unit block as follows.
With the CPU Unit Terminal block, contact input/output to another function
block must go via the Contact Distributor block (Block Model 201) or the Step
Ladder Program block (Block Model 301). Whereas, with the Extended CPU
Unit Terminal block, contact input/output is possible without going via the
Contact Distributor block (Block Model 201) or the Step Ladder Program
block (Block Model 301).
Note 2
When the CPU Unit Terminals are used to exchange data with the Contact
I/O Unit allocated CIO Area, data exchange functionally is the same as when
the Field Terminal blocks are used to perform data exchange.
Note 3
Do not write to the same I/O memory addresses when exchanging data
between the Loop Control Unit and the CPU Unit.
Connecting to CX-Process Tool
Peripheral port or RS-232C port
CPU Unit
Loop Control Unit
Function block data prepared on
CX-Process Tool running on
computer
Function block
data
The Loop Control Unit achieves all functions by combining function blocks.
Function block data must be prepared on CX-Process Tool and then
downloaded to the Loop Control Unit for use.
The tag settings for CX-Process Monitor must also be prepared on CX-
Process Tool.
CX-Process Tool runs on a computer that is connected to the peripheral port
or RS-232C port of the CPU Unit. (The Host Link can be used in the serial
communications mode but not on the Peripheral bus.)
CX-Process Tool is installed on a computer on which the Controller Link
Support Board is mounted, and function block data can be downloaded from
CX-Process Tool to the Loop Control Unit via the Controller Link.