Exchanging Data with the CPU Unit
Section
3-3
114
3-3 Exchanging Data with the CPU Unit
The Loop Control Unit exchanges the following two types of data with the
CPU Unit:
1. Mutual exchange of run status
2. Exchange of any data
3-3-1
Mutual Exchange of Run Status
The run status of the Loop Control Unit and the CPU Unit can be monitored
mutually by the following two areas:
Allocated CIO area for CPU Bus Unit:
Run status of Loop Control
Unit is sent to the CPU Unit.
System Common blocks (Block Model 000): Run status of the CPU Unit is
sent to the Loop Control Unit.
Note
The system information and Node Terminal data are also reflected in the
Data Memory for the Node Terminals. These data, however, are exclusively
for CX-Process Monitor.
3-3-1-1
Run status of CPU Unit
The run status of the CPU Unit is reflected in ITEM007 to ITEM011 and
ITEM13 of the System Common block at all times. For this reason, the
required processing can be executed on the Loop Control Unit by the Step
Ladder Program block (Block Model 301) or other blocks based on the
contact output of the System Common block.
Loop Control Unit
CPU Unit
System Common
block
CPU Unit run status in System Common block
ITEM
1 (ON)
0 (OFF)
007
Fatal error (fatal error detected by
system self-diagnostics or
execution of FALS instruction)
Not fatal error
008
CPU Unit running (RUN mode or
MONITOR mode)
Stopped (PROGRAM mode or
fatal error)
009
Output OFF (Auxiliary Area A50015
turns ON.)
Not output OFF
010
RUN mode
Not RUN mode
011
MONITOR mode
Not MONITOR mode
013
PROGRAM mode
Not PROGRAM mode