Canopen communication – Lenze 931K User Manual
Page 54
CANopen communication
Node guarding telegram
Telegram structure
l
54
KHB 13.0002−EN 4.1
Status of NMT slave
Value s
Bit (s)
6
5
4
3
2
1
0
Stopped
04
h
0
0
0
0
1
0
0
Operational
05
h
0
0
0
0
1
0
1
Pre−operational
7F
h
1
1
1
1
1
1
1
Guard time
The time interval with which the NMT master sends the RTR telegram is the "Guard time",
object 100C. For each NMT slave, an individual time interval can be set.
The RTR prompts the NMT slave to send its current data.
Monitoring starts with the first remote request received from the master. From this time
on, the remote requests must be received before expiry of the set monitoring time.
Otherwise, error 46 will be activated.
If the monitoring time is set to zero, the node guarding monitoring is deactivated.
Node life time
The "node life time" is the product of the guard time" and the life time factor":
Node life time = life time factor x guard time
"Life time factor" and "guard time" have to be known to the NMT master. For this, the
values from the NMT slave are read at each restart, or defined values are sent to the NMT
slave at each restart.
For each NMT slave an individual node life time" can be set.
OK status
The status of the connection is ok ("OK status") if
ƒ
the NMT slave has received a request from the NMT master within the "node life
time" and
ƒ
the NMT master has received a correct response from the NMT slave within the
"node life time".
In the OK status, the monitoring times for the NMT master and the NMT slave are reset and
the node guarding telegram is continued.