Lenze EPM−T9XX Modular system - Manual (Page 195)

Node Guarding
8
Networking via system bus (CAN)
8.6
L
8.6−1 EDSPM−TXXX−9.0−11/2009
8.6 Node Guarding
COB-ID = 1792 + Node-ID
COB-ID = 1792 + Node-ID NMT-Slave 1 ) NMT-Master
indication
indication
indication
request
request
confirm
confirm
indication
Remote transmit request
Remote transmit request
response
response
Node Guarding Event 2 ) Life Guarding Event 2
Node
Guard
time
Node
Time
Life
0
0
1
1
t s
7 6 … 0
t s
7 6 … 0
epm−t133
Fig. 8.6−1 Node Guarding Protocol
1) I/O system IP20
s Status of the I/O system IP20
T Toggle bit
The Node Guarding Protocol monitors the connection between master and slave.
Via the index I100C
h
"Guard time", a time [ms] can be set and in the index I100D
h
"Life time factor" a factor can be set. If both indices are multiplied by each other,
you get a monitoring time in which the master must send a Node Guarding
telegram to the slave. If one of both indices is set to zero, the monitoring time is
also zero and hence deactivated. The slave sends a telegram with its current status
to the master.
With event−controlled process data transmission, Node Guarding ensures cyclical
node monitoring.
l The master starts the Node Guarding by sending the Node Guarding
telegram.
l If the slave (I/O system IP20) does not receive a telegram within the
monitoring time, the Node Guarding Event is activated. The I/O system IP20
switches to the state set in I1029
h
. The outputs switch to a defined state
(also see the chapter Configuration
® Diagnostics).
l A change to the Operational status triggers a reset.
Description