Program Example - Mitsubishi Electric Q Series Reference Manual

6 PROGRAMMING

6.1.2 Program example

Interactive communication program with station No.2
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Interlocks should be applied to the programs according to the link status of the host
and other stations.
The following example shows an interlock in the communication program that uses the
link status of the host (SB0047, SB0049) and the link status of station number 2
(SW0070 bit 1, SW0074 bit 1).
(Example)
Set the following values for the timer constant K .
Baton pass status
(T0, T2)
Cyclic transmission status
(T1, T3)
Reason: This way the control is not stopped even if the network detects an
instantaneous error due to a faulty cable condition and noise interference.
Also, the multipliers of 6, 2 and 3 should only be considered as a guideline.
REMARKS
For further information on interlocks for special link instructions, refer to Section
7.4.5.
SB47: Baton pass status(host)
SB49: Host data link status
SW70: Baton pass status of each station
SW74: Cyclic transmission status of each station
SB20: Module status
More than (link scan time
More than (link scan time
6) + (target station CPU sequence scan time
3)
MELSEC-Q
2)
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