Mitsubishi Electric MELSEC iQ-R Series User Manual page 59

Buffer area name
NMT state
*1 The latest NMT state in which the NMT master instructed each NMT slave through node control. If nothing was instructed, the NMT state
of each NMT slave is that of the point when the NMT master started monitoring.
NMT slave information detected by the NMT master is stored in 'NMT error control status' (Un\G401 to Un\G527) and 'NMT
state' (Un\G601 to Un\G727). ( Page 168 NMT error control status (Un\G401 to Un\G527), Page 169 NMT state
(Un\G601 to Un\G727))
■Error detection by the NMT slave
The NMT slave (2) monitors polling from the NMT master (1) to detect errors of the NMT master. If the NMT slave is not polled
by the NMT master within the life time, the NMT slave determines that an error has occurred in the NMT master. In this case,
the CAN ERR LED of the NMT slave turns on or flashes.
(1)
(2)
: Polling
: Response
NMT slave information detected by the NMT master is reflected in the following buffer memory areas.
Buffer area name
NMT error control status
NMT master information detected by the NMT slave is stored in 'NMT error control status' (Un\G401 to Un\G527). ( Page
168 NMT error control status (Un\G401 to Un\G527))
■Setting method
Use parameters to set the node guarding function. For details, refer to the following.
Page 96 "NMT slave" window
When node guarding is executed for an NMT slave, it must also be executed for the NMT master. However,
when node guarding is executed for the NMT master, whether to execute it for an NMT slave is optional.
The NMT master starts executing polling in either of the following timings.
• When an NMT slave boots
• When "Node guarding start" is requested to the guarding request of the object dictionary
An NMT slave starts monitoring polling by the NMT master in the following timing.
• When the first polling message is received from the NMT master
Details reflected
The NMT state obtained from each NMT slave through polling is stored.
The obtainable NMT states are as follows.
• Stop state
• Operational state
• Pre-operational state
GuardTime GuardTime
Node life time
Details reflected
For node guarding for each NMT slave, the following statuses are stored.
• Node guarding is enabled/disabled (running/stopped).
• There was no polling from the NMT master within the guard time.
• There was no polling from the NMT master within the life time.
1 FUNCTIONS
57
1.8 Node Guarding
1