Nmt Services - Error Control Services - Siemens Sinamics S120 Commissioning Manual

2.4.5

NMT services - Error Control Services

Note
In the basic setting, both methods "Life Guarding" and "Heartbeat" are deactivated.
Node guarding protocol and heartbeat protocol cannot be used at the same time. As soon as
the "heartbeat producer time" is not equal to zero, the heartbeat protocol is used
automatically.
Life guarding
The NMT master Issues monitoring queries using the node guarding protocol. The slave's
answer contains information about its state. If one of the NMT slaves addressed does not
reply within a certain time window ("Node lifetime") – or the state of the NMT slave has
changed – then the NMT master informs its master application.
The NMT slave supports "Life guarding" (NMT slave monitors the NMT master). For this
purpose, the entries for "Guard time" and "Life time factor" are used from its object directory
to write its "Node life time". The "Node lifetime" results from the "Node guard time" multiplied
by the "Lifetime factor". The "Node lifetime" corresponds to p8604.
If the NMT slave is not addressed/monitored by the NMT master within its "Node lifetime", it
informs its local application of this using a "Life guarding event". If the entries for "Guard
time" and "Lifetime factor" in the slave's object directory are at "0" (default setting), then the
NMT slave does not monitor the NMT master.
Monitoring of the NMT slave starts when the first "Remote transmit request" (RTR) is
received from the NMT master via its COB ID. The activated and initiated "life guarding
monitoring" is displayed via the PROFIdrive PZD state "Fieldbus oper" r8843.2.
In the case of a CAN communication error, e.g. too many message frame failures,
SINAMICS issues fault F08700 with fault value 2 (for details see SINAMICS S120/150 List
Manual). The fault is displayed in parameter r0949. The reaction of the drive to the fault is
set with p8641.
The values for the "Node guard time" and the "Lifetime factor" are stored in the appropriate
NMT slave's object directory.
Heartbeat
The SINAMICS drive only supports the "Heartbeat producer protocol".
A "Heartbeat producer" (CANopen device) issues heartbeat messages periodically.
CANopen devices in the network recognize this heartbeat message. If a heartbeat cycle of
the "Heartbeat producer" is missing, a Heartbeat Consumer can respond to this.
CANopen interface
Commissioning Manual, 11/2017, 6SL3097-4AA00-0BP3
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2.4 Network management
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