Lenze DDS Global Drive PLC Developer Studio - Manual (Page 12)

2.3 Monitoring mechanisms
Function library LenzeCanDSxDrv.lib
Introduction
2−4
L
LenzeCanDSxDrv.lib EN 1.2
2.3.2 "Node Guarding"
Unlike the "Heartbeat" monitoring mechanism, "Node Guarding" requires a polling message from the
monitoring bus device (NMT master).
Node
Life
Time
Node
Guarding
Event
Indication
Response
Confirmation
Confirmation
Response
Request
Request
Indication
Node
Guard
Time
NMT Master NMT Slave
RTR
t s
t s
RTR
Life
Guarding
Event
Node
Life
Time
1 8
1 8
t:
Stopped
Operational
Pre-Operational
Boot-Up Event
Toggle bit
s: NMT Slave state:
4
5
127
0
·
The monitoring bus device (NMT master) cyclically polls every bus device to be monitored
(NMT slave) using a node−specific remote transmission request telegram.
·
As response, the bus device to be monitored (NMT slave) returns its communication status.
·
Unless the monitoring bus device (NMT master) receives the message from the bus device to
be monitored (NMT slave) within the selected monitoring time ( NodeLifeTime), a "Node
Guarding" event will be indicated.
·
If the status of the monitoring bus device (NMT master) is not polled within its "Node Lifetime",
a "Life Guarding" event will be indicated at the bus device to be monitored (NMT slave).