hi, finally i found the issue ... on my CAN-bus there are several CanOpen and J1939 devices. To keep the busload as low as possible i set the CanOpen PDO's to different interval-times. Therefore every few minutes/hours (depending on the chosen timings) all PDO's need to get handled at the same time. This "spike" in bus-load and especially cpu-load required way too much processing-time and exceeded the cycletime of the CPU. means: i've chosen 10ms as minimum CPU taskcycle during "spike": the CPU taskcycle-time...