Exchanging Data with CX-Process Monitor/SCADA Software and with Other Nodes
Section
3-4
123
1. System information
2. Data of Node Terminal block (Area to send to computer, Area to send to
all nodes, Area to receive from all nodes)
3-4-1-1 System
information
System information is information such as the unit address of the Loop
Control Unit and run status. This information is reflected in the 24 words (8
words per Loop Control Unit) from the leading word of the Data Memory (D)
for Node Terminals when the Loop Control Unit starts to be run.
CPU Unit
Data Memory (D)
Area in I/O memory
Leading address in Data
Memory for Note Terminals
→
LCU number: 2
LCU number: 1
LCU number: 0
8 words
System
information
(8 words)
System
information
(8 words)
System
information
(8 words)
8 words
8 words
Note
The default leading address of the Data Memory (D) for Node Terminals is
D16020 or LCU number 0. Accordingly, the system information is stored to
eight words of D16020 to D16027 as the default addresses when running
of the Loop Control Unit is started. For this reason, when the Loop Control
Unit is used at its defaults, do not use words D16020 to D16027 for other
applications.
When two or more Loop Control Units are used on the same CPU Rack,
the LCU number (ITEM042) for identifying the Loop Control Unit must be
set to different values for each of the Loop Control Units. Also, the leading
address (ITEM043) of the Data Memory (D) for Node Terminals must be
set to the same value for each of the Loop Control Units.
The following table shows the details of system information:
Data location
Offset
address
Data description
Block
address
ITEM
Default address in
I/O memory for block
address 000
+0
Unit address
041
D16020
+1
Loop Control Unit run status
D16021
+2
CPU Unit run status
007 to 013
D16022
~
~
Role: 0
+7
Data update check code
000
D16027
+0
Unit address
041
D16028
+1
Loop Control Unit run status
D16029
+2
CPU Unit run status
007 to 013
D16030
~
~
Role: 1
+7
Data update check code
000
D16035
+0
Unit address
041
D16036
+1
Loop Control Unit run status
D16037
+2
CPU Unit operation status
007 to 013
D16038
~
~
Role: 2
+7
Data update check code
000
D16043