NORD Drivesystems BU0550 - Manual (Page 70)

PLC logic for NORD SK 54xE frequency inverters
70 BU 0550 GB-0813
3.5.7.2 FB_NMT
After a Power UP all CAN participants are in pre-operational bus status. In this state, they can neither
transmit nor receive a PDO. In order for the PLC to be able to communicate with other participants on the
CON bus, these must be set to an operational state. Usually, this is performed by the bus master. If there is
no bus master, this task can be performed by the FB_NMT.
The status of all participants which are connected to the bus can be controlled via the inputs PRE, OPE or
STOP. The inputs are adopted with a positive flank on EXECUTE. The function must be repeatedly called
up until the output DONE or ERROR has been set to 1.
If the output ERROR has been set to 1, there is either no 24V supply to the RJ45 CAN socket of the inverter
or the CAN driver of the inverter is in the status Bus off.
With a negative flank on EXECUTE all outputs are reset to 0.
Table 96 FB_NMT
VAR_INPUT VAR_OUTPUT
Input Explanation Type Output Explanation Type
EXECUTE Execute BOOL DONE NMT command is transmitted BOOL
PRE Sets all participants to
Pre-Operational status BOOL ERROR Error in FB BOOL
OPE Sets all participants to
Operational status BOOL
STOP Sets all participants to
Stopped status BOOL