Transient Transmission - Mitsubishi Electric MELSEC iQ-R Series User Manual

16.2

Transient Transmission

When receiving requests from a user program which uses dedicated functions or from CW Configurator, this function
communicates with other stations on the same or different network via a network module controlled by this product.
Precautions
■Executing a MELSEC data link function simultaneously from multiple user programs
When executing a MELSEC data link function simultaneously from multiple user programs, a request for the transient
transmission processing of the next user program is sent after that processing of the previously executed user program is
completed. Therefore, executing multiple user programs simultaneously may lead to extended time from the execution to the
completion of a MELSEC data link function in some of the user programs.
Corresponding MELSEC data link functions are shown as below:
• mdControl function
• mdDevRstEx function
• mdDevSetEx function
• mdGetLabelInfo function
• mdRandREx function
• mdRandRLabelEx function
• mdRandWEx function
• mdRandWLabelEx function
• mdReceiveEx function
• mdSendEx function
• mdTypeRead function
■Communication timeout value of the MELSEC data link function setting function
A communication timeout value which is set using the MELSEC data link function setting function is not a timeout time from
the execution to the completion of a MELSEC data link function. It is a timeout time to monitor the time taken from when a
request is sent to an access target to when the response is returned via transient transmission. Set an appropriate time
according to the time when an access target system returns the response.
Corresponding MELSEC data link functions are shown as below:
• mdControl function
• mdDevRstEx function
• mdDevSetEx function
• mdGetLabelInfo function
• mdRandREx function
• mdRandRLabelEx function
• mdRandWEx function
• mdRandWLabelEx function
• mdReceiveEx function
• mdSendEx function
• mdTypeRead function
16 NETWORK MODULE ACCESS FUNCTION
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16.2 Transient Transmission