Precautions For Data Communications Using Auto Refresh; Example Of Parameter Setting For Interlock Program - Mitsubishi Electric Q12DCCPU-V User Manual

13
COMMUNICATIONS BETWEEN CPU MODULES

(3) Precautions for data communications using auto refresh

CPU
No.
No.1
No.2
Depending on the timing of writing data to the host CPU's auto refresh area or reading
data from another CPU, old and new data may be mixed in the area for each CPU.
Therefore, configure an interlock program for auto refresh so that data of another
CPU will not be used when old and new data are mixed.
(a) Interlock program example
Figure 13.15 shows an interlock program example for sending data from CPU
No.1 (programmable controller CPU) to CPU No.2 (C Controller module).
Table 13.11 Example of parameter setting for interlock program
Auto refresh setting for CPU No.1
CPU specific send
Transfer
range
No.
Points Start End Start End
Transfer 1 2 0 1
Transfer 2 10 2 11
Transfer 1 2 0 1
The parameter setting in Table 13.11 uses the following interlock devices.
• M0 as an interlock device (Data set completion bit) of CPU No.1
• M32 as an interlock device (Data processing completion bit) of CPU No.2
13.3 Data Communications Using CPU Shared Memory
Device
Direction CPU
setting
M0 M31
No.1
D0 D9
M32 M63 No.2
13.3.2 Data communications using auto refresh
Auto refresh setting for CPU No.2
CPU specific send
Transfer
range
No. No.
Points Start End
Transfer 1 2 0
Transfer 2 10 2
Transfer 1 2 0
13
9
10
11
1
11
1
12
13
14
15
16
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