User Documentation

Configuration

15.3.2.1 Telegram losses

If a telegram loss is detected on the EtherCAT bus, a message is reported.

Depending on the value of the configuration parameter frameLossToler-

ance, this message is reported either as an error or as a warning.

The message is reported as a warning if the number of telegram losses in

the last ten transmissions has not exceeded the telegram loss tolerance con-

figurable by the configuration parameter frameLossTolerance. If several

telegrams are transmitted per bus cycle, all telegrams are included for the

tolerance limit, i.e. if, for example, five telegrams are transmitted per bus cy-

cle, the tolerance limit is reset after two successfully transmitted bus cycles.

The error status of the end points affected by the process data is not

changed. The process data of the affected end points are not updated in this

cycle.

WARNING Ackn (6353/72), ECAT: At least one Ethernet frame was

lost in the EtherCAT segment.

If it occurs repeatedly with exceeding of the tolerance limit, the message is

sent as an error.

ERROR Ackn (6353/2), ECAT: At least one Ethernet frame was

lost in the EtherCAT segment.

The error status of the end points affected by the process data are only set

invalid if the cyclic command present in the affected telegram is not transmit-

ted several times in succession and the telegram losses tolerance has been

exceeded.

15.3.2.2 Timing problems

If a timing problem is detected on the EtherCAT bus, a message about the

time violation occurs. Possible causes are:

● 'DMA': The configured DMA duration (dmaTime) was exceeded. Not all

data could be read from the RAM buffer within the specified time.

● 'SW normal': The time required for the update in the control context was

higher than the offset of the standard frame (startOffset). No data could

be written into the RAM buffer.

● 'SW early': The time required for the update (especially the application

code for fast control) in the control context was higher than the offset of

the early frame (earlyStartOffset).

The cause of the time violation is visible as a parameter in the error text.

If a timing violation occurs, all further telegrams whose transmission was

scheduled for this cycle after the affected telegram are also invalid. The re-

sulting failure of several telegrams in one cycle is counted as one timing vio-

lation.

If no timing violation has occurred within the last ten EtherCAT bus cycles,

the message is reported as a warning. The error status of the end points af-

fected by the process data is not changed. The process data of the affected

end points is not updated in this cycle.