Lenze DDS System bus CAN for PLC - Manual (Page 168)

11.10 L_CanDSxNodeGuarding − carrying out a "Node guarding"
System bus (CAN) for Lenze PLC devices
LenzeCanDSxDrv.lib function library
11−12
L
PLC−Systembus EN 2.0
11.10 L_CanDSxNodeGuarding − carrying out a "Node guarding"
Function block
Use this FB to cyclically monitor the CAN connection between the PLC and other system bus nodes
by means of the so−called "Node guarding" mechanism.
·
This monitoring mechanism first has to be initialised in the CanDSx driver using the function
L_CanDSxOpenNodeGuarding.
( ^ 11−11)
L_CanDSxNodeGuarding
tNodeGuardTime
wDrvNr
byNodeAddr
bRun CTRL
nState
NMT Slave
(Node address = ) byNodeAddr
System bus
(CAN)
š
byNodeLifeTimeFactor
1.
2.
š
FB call in: o Cyclic task
(PLC_PRG)
Þ Time−controlled task
(INTERVAL)
o Event−controlled task
(EVENT)
o Interrupt task
Inputs Data type Information/possible settings
wDrv Word Driver number for the CAN interface of the PLC that is to be used
10 On board system bus (CAN)
byNodeAddr Byte Node address of the node to be monitored.
1...128 Node address
bRun Bool Activating the "Node guarding".
TRUE Monitoring is activated.
·
The FB now sends a "remote transmission request" telegram in the
transmission cycle set via tNodeGuardTime to the node with the node address
byNodeAddr
and waits for a corresponding response. If it is not effected within
the "NodeLifeTime" monitoring time, the FB outputs a corresponding status at
the output nState.
tNodeGuardTime Time Transmission cycle of the remote transmission request telegram.
·
Time interval in which the PLC sends a status request to the node to be monitored (cyclic
polling).
·
This setting has to correspond to the "Guard Time" set in the PLC to be monitored (C0382).
byNodeLifeTimeFactor Byte Factor for the so−called "NodeLifeTime".
"NodeLifeTime" = byNodeLifeTimeFactor
ž tNodeGuardTime
·
If the node to be monitored does not respond to the status request of the PLC within the
"NodeLifeTime", a "Node Guarding" event is actuated (nState = −10).
·
This setting has to correspond to the "NodeLifeTimeFactor" set in the PLC to be monitored
(C0383).