Lenze DDS Global Drive PLC Developer Studio - Manual (Page 23)

Function library LenzeCanDSxDrv.lib
Functions/function blocks
3.9 L_CanDSxNodeGuarding − Execution of "Node Guarding"
3−11
L
LenzeCanDSxDrv.lib EN 1.2
3.9 L_CanDSxNodeGuarding − Execution of "Node Guarding"
Function block
This FB is used for the cyclic monitoring of the CAN connection between the PLC and other system
bus devices by means of the "Node Guarding" mechanism.
·
Before the function is executed, the "Node Guarding" monitoring mechanism must be
initialised in the CanDSx driver by means of the function L_CanDSxOpenNodeGuarding.
( ^ 3−10)
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 Drive number for the CAN interface of the PLC
10 On board system bus (CAN)
byNodeAddr Byte Node address of the bus device to be monitored.
1 ... 128 Node address
bRun Bool Activation of "Node Guarding".
TRUE Monitoring is activated.
·
The FB uses the transmission cycle selected under tNodeGuardTime, sends a
remote transmission request telegram to the bus device with the node address
byNodeAddr and expects a corresponding response. If the response is not
received within the monitoring time ("NodeLifeTime"), the FB will output the
corresponding status at nState.
tNodeGuardTime Time Transmission cycle of the remote transmission request telegram.
·
Time interval in which the PLC sends a status enquiry to the bus device to be monitored (cyclic
polling).
·
The setting must correspond to the "GuardTime" (C0382) selected in the PLC to be monitored.
byNodeLifeTimeFactor Byte Factor for the "NodeLifeTime".
"NodeLifeTime" = byNodeLifeTimeFactor ž tNodeGuardTime
·
Unless the bus device to be monitored responds to the status enquiry within the
"NodeLifeTime", a "Node Guarding" event will be activated (nState = −10).
·
The setting must correspond to the "NodeLifeTimeFactor" (C0383) selected in the PLC to be
monitored.