Control Cycle Times When Cascading Data Transmission Paths - Leuze electronic DDLS 538 Series Original Operating Instructions

EtherCAT
Minimum cycle time when using a DDLS 538 ... S2
Minimum cycle time = 5 ms / value of the "EtherCATMaxMissingFrames" parameter of the control.
Examples:
• PLC with defined value for Lost Frames counter 10
Minimum cycle time = 5 ms / 10 = 500 µs
• NC with defined value for Parameter "EtherCATMaxMissingFrames" of 3
Minimum cycle time = 5 ms / 3 = 1666 µs
Minimum cycle time when using a DDLS 538 ... S3
Minimum cycle time = 70 ms / count of the "EtherCATMaxMissingFrames" parameter
The "EtherCATMaxMissingFrames" parameter can be configured in wide ranges. To calculate the mini-
mum control cycle time, the count of the "EtherCATMaxMissingFrames" parameter is used.

Control cycle times when cascading data transmission paths

For the calculation of the cycle times with cascading, a distinction must be made as to whether or not an
EtherCAT slave participant is installed between the two data transmission paths (see chapter 7.4.4 "Control
cycle times when cascading data transmission paths").
• When cascading with an EtherCAT slave participant between the data transmission paths, the mini-
mum control cycle times are calculated as specified.
• When cascading without an EtherCAT slave participant between the data transmission paths, the cal-
culated minimum cycle times of the given used control are doubled.
Behavior if the value for the released cycle times is not met
If the calculated cycle time is not met by the used control, signaling of an interrupted network topology
through the data transmission path to the preceding EtherCAT participant cannot occur in good time (Oper-
ationally related interruption of the EtherCAT communication).
As a result, the value of the "EtherCATMaxMissingFrames" parameter is exceeded and the Operational op-
erating mode of the EtherCAT master is deactivated.
NOTICE
EtherCAT participants not addressable!
If the EtherCAT master exits the Operational operating state, the sensors and actuators are no
longer actuated.
For moving machine or system parts, this can result in an emergency stop of all axes.
NOTICE
If a shutdown of the EtherCAT hardware LAN connection (Phy) occurs at the stationary
mounted DDLS 538 due to an interruption, the DDLS 538 (... S2 as well as ... S3) is able to
transmit data again after 1.5 s.
TwinCAT cyclically attempts to set the EtherCAT master to the Operational operating state.
In doing so, the EtherCAT master runs through the Init > Pre-Operational > Safe-Operational >
Operational operating states.
In the Operational operating state of the EtherCAT master, the EtherCAT participants are again
addressable.
Leuze electronic GmbH + Co. KG DDLS 538 ... 57