Baumer GNAMG User Manual
Page 13
Manual_GNAMG_CANopen_EN.doc
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Baumer IVO GmbH & Co. KG
21.11.12
Villingen-Schwenningen, Germany
Node und Life Guarding
For user guarding either the heartbeat
protocol (default) or the nodeguarding
protocol (object 2110h Bit 5 = 1) can be
applied.
The NMT master is able to form a data
bank with the corresponding NMT states of
every single user. This protocol is for
guarding whether a user has left the bus.In
addition, every user can monitor whether
the control is still active.
The NMT master starts the guarding
service by a Remote Frame to the
requested user. Every Remote Frame will
reset the Life-Time at the user. Further the
user responds his NMT state. This way, the
NMT master is able to check whether the
user is in the correct NMT state and can
react correspondingly in case of error.
Upon Life-
Time expiry a „Node Event“ will
be triggered. The behaviour in case of error
is defined in object 1029h-1h
“Communication Error”.
Example of a nodeguarding protocol:
COB-ID
Data/ Remote
Byte 0
701h
r
00h (0d)
701h
d
FFh (255d)
701h
r
00h (0d)
701h
d
7Fh (127d)
Possible user NMT-states:
0:
BootUp-Event
4:
Stopped
5:
Operational
127:
Pre-Operational
In this example the lower 7 bits equal 7Fh, i.e. the inclination sensor is in pre-operational mode.