Mitsubishi Electric MELSEC iQ-R Series User Manual page 66

Data transmission timing
The data transmission condition or timing varies depending on the setting of 'Pre-defined Layer 2 message configuration'
(Un\G6000 to Un\G6167). ( Page 176 Pre-defined Layer 2 message configuration (Un\G6000 to Un\G6167))
The following describes each setting and timing of transmission.
However, regardless of the transmission type, data is transmitted at the time of transition to online mode and also against a
send request by 'Message transmit trigger request' (Y4).
■When the transmission type is Event
Data is sent every time 'Data exchange request' (Y1) is turned on and data exchange is completed.
■When the transmission type is Event (COS)
Data is sent every time 'Data exchange request' (Y1) is turned on and data exchange is completed. However, data is not sent
if it is not changed even when 'Data exchange request' (Y1) is turned on and data exchange is completed.
■When the transmission type is Cycle
Data is sent every time the set cycle time has passed.
■When the transmission type is Cycle (COS)
Data is sent every time the set cycle time has passed.
However, regardless of the execution of 'Data exchange request' (Y1), data is not sent if it is not changed even after data
exchange is completed.
■When the transmission type is Transmit trigger only
Data is sent each time a send request is made by 'Message transmit trigger request' (Y4).
For details on how to make a send request by 'Message transmit trigger request' (Y4), refer to the following.
Page 150 Message transmit trigger completed (X4), Message transmit trigger request (Y4),Page 182 Message transmit
trigger flags (Un\G8400 to Un\G8402)
• Regardless of the transmission type setting, at the time of transition to online mode, send data is
automatically updated and sent. Note that to update send data afterward, 'Data exchange request' (Y1) is
required.
• When Auto RTR response is selected for RTR response setting, regardless of "Transmission type", data is
sent also when a remote transmission request is received.
1 FUNCTIONS
64
1.11 Layer 2 Message Transmission and Receive