Program Example For Acyclic Communication With Dp-Slaves - Mitsubishi Electric Melsec Q Series User Manual

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PROGRAMMING

7.9.4 Program example for acyclic communication with DP-Slaves

If a system switching occurs, the function of the acyclic communication with DP-Slaves
cannot be continued.
In redundant systems, do not use the acyclic communication with DP-Slaves.
To use the function, pay attention to the descriptions given below and fully examine the
possible operations in advance.
(1) Application types and precautions
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- 83 7.9 Program Examples for Use in the Redundant System
7.9.4 Program example for acyclic communication with DP-Slaves
The Acyclic communication with DP-Slaves must be utilized for temporary
*1
applications .
If it is used for a constant application
system to operate in the manner shown in (a) and (b). Therefore, fully examine the
system for any problem.
* 1 Parameter settings of DP-Slaves, temporary status monitoring, etc.
* 2 Constant status monitoring, etc.
(a) When using Class 1 service
When system switching occurs during acyclic communication with DP-Slaves,
and if an error occurs, states of communication with DP-Slaves are initialized.
(Inputs and outputs are turned OFF.)
(b) When using Class 2 service
If system switching occurs before execution of the ABORT service, the INITIATE
service is not completed normally in the new control system.
In this case, after the time for the INITIATE service transmission timeout has
elapsed, execute the INITIATE service again.
*2
, system switching causes the new control