Lenze DDS System bus CAN for PLC - Manual (Page 153)

System bus (CAN) for Lenze PLC devices
LenzeCanDrv.lib function library
10.7 L_CanPdoTransmit − transmitting a CAN object
10−11
L
PLC−Systembus EN 2.0
Forced transmission
Some cases may require an entry of a transmit request in the transmit request memory without
considering a data change (event−controlled) or a cycle time (time−controlled).
For this purpose, the L_CanPdoTransmit FB supports the action SendData in the "Forced
transmission" transmit mode (byTransmitMode = 3).
Example
Declaration of the function block in ST:
SendWithID678: L_CanPdoTransmit; (* send data with identifier 678 *)
Calling the function block in ST:
SendWithID678 (wDrvNr:=10,
byLen:=8,
dwCobID:=678,
pIOAdress:=
ADR(abySendData),
tRepeatTime:=T#5ms,
byTransmitMode:=3);
Action "Forced transmission" in ST:
SendWithID678. SendData; (* force send procedure *)
Note!
The use of an address which is stored in the memory area of the operating system is not permitted
for the L_CanPdoTransmit and L_CanPdoReceiveFBs!
Problem:
The addresses of the system variables (inputs/outputs of system
blocks) are also placed in the memory area of the operating system, in
the following illustration the system variable AIN1_nIn_a: Remedy:
Instead of the address of the system variable, use the address of a
temporary variable, which the value of the corresponding system
variable is copied into:
ADR
2
AIN1_nIn_a
L_CanPdoTransmit
wDrvNr
byLen
dwCobId
pIOAdress
tRepeatTime
byTransmitMode nState
wNrOfCallsToSend
10
8
750
t#10ms nAnalogInput
AIN1_nIn_a nAnalogInput
ADR
2
L_CanPdoTransmit
wDrvNr
byLen
dwCobId
pIOAdress
tRepeatTime
byTransmitMode nState
wNrOfCallsToSend
10
8
750
t#10ms