Description of the behaviour:
In the event of an error, the following network communication is no longer answered by the Lenze Profinet device:
- Profinet acyclic parameter communication (DP-V1)
- Profinet neighbourhood detection LLDP
- Lenze engineering communication (EASY Starter)
- Ethernet ARP, ICMP pings, etc. (services that are frequently sent by router gateways in a network)
The PROFINET status reported to the i950 TA application remains frozen (parameter 0x2388="0x107", "Connected"), the PROFINET LED BUS-RDY lights up green constantly.
The PROFINET input data (actual values of the i950) continue to be sent at the parameterised interval time.
The PROFINET master recognises the error and stops the IO data communication to the affected device and the following error messages are entered in the PLC logbook (in ascending order):
- Failure of an IO device - Timeout in the acyclic PROFINET services
- Failure of an IO device - IO device not found
- Partner error - No neighbour could be detected
(if neighbour detection is parameterised)
The controller must be restarted (by switching to mains or setting parameter 0x2022:035 = 1 (restart device)).
Under what conditions does the behaviour occur?ARP request packets that are sent to the PROFINET subnet at a regular and high frequency (burst). Such bursts are typically sent by a central router gateway. The larger the network, the more ARP request packets are sent.
Parallel communication of Ethernet IP telegrams with the affected device,
e.g.: acyclic PROFINET parameter communication, EASY Starter communication, SNMP, ...
Note:
The behaviour described does not occur if the user only uses PDO communication with the Lenze Profinet device.
Which products are affected?
Controller c520
Controller c550
Short-term measures/evaluation/recommendations:Reduce the ARP request burst load by parameterising the gateway causing the burst accordingly.
If possible, map acyclic Profinet communication services to the PDO data channel.
Reduce or set the IP communication with the affected Lenze device.
