Flying Master - Mitsubishi Electric MELSEC iQ-R Series User Manual

Flying master

Flying master is a function to continue network control by making one of its own nodes to become the NMT master (2) when
the NMT master in the same network is in failure (1).
Among those flying masters, the CANopen node that works as the actual NMT master is called the active NMT master, and
the other CANopen nodes are called the hot standby NMT masters.
(1)
Function details
Flying masters monitor errors of each other via heartbeat. ( Page 58 Heartbeat)
When an error of the active NMT master is detected via heartbeat, NMT flying master negotiation is executed so that the flying
master with the highest priority becomes the active NMT master.
■Flying master priority
The flying master priority is determined in the following way.
• A flying master with a higher NMT master priority level has a higher flying master priority. (High > Medium > Low)
• If flying masters have the same NMT master priority level, a flying master with a smaller node ID has higher priority.
■Setting method
Use parameters to set flying masters. For details, refer to the following.
Page 93 "NMT master / slave" window
■Precautions
When using the flying master function, pay attention to the following.
• When the active NMT master is in failure, network communications will be reset and applications will be interrupted.
• The flying master function does not provide data synchronization with applications. Data synchronization requires
appropriate CANopen setting and system design.
• Configure the flying master setting properly. NMT flying master negotiation may not work properly if the setting is incorrect.
Also, test the system configuration before using the flying master function.
1 FUNCTIONS
24
1.2 NMT
Standby NMT master → Active NMT master
(2)