Difference Between Ddls 538; Calculation Of The Control Cycle Time - Leuze electronic DDLS 538 Series Original Operating Instructions

EtherCAT
• due to insufficient alignment at distant or close range
• Due to an interruption of the EtherCAT connection (LAN cable) to the downstream participant after the
mobile DDLS
• Due to an interruption of the voltage supply of the mobile DDLS
• Due to an interruption of the voltage supply of the downstream participant on the mobile side
• Due to activation of the ADJ operating mode (adjust mode for fine adjustment)
Due to the interruption, the EtherCAT participants are no longer addressable after the data light path.
In the stationary mounted optical data transceiver, a retriggerable timer is started for an internal delay time.
After the timer has elapsed, the copper link (Phy shutdown) of the stationary DDLS 538 ... is deactivated if
the interruption still exists. If the interruption no longer exists after the timer has elapsed, the copper link re-
mains in place.
This measure signals an interrupted network connection to the preceding participant. It returns EtherCAT
protocols directly to the master.
7.4.2 Difference between DDLS 538 ... S2 and DDLS 538 ... S3
Both models respond to interruptions with different internal delay times.
Tab. 7.1: Difference DDLS 538 ... S2 / DDLS 538 ... S3
DDLS model
DDLS 538 ... S2
DDLS 538 ... S3
Particularly if the opening angle is exceeded due to external vibrations/oscillations, a delay of 70 ms of the
Phy shutdown (DDLS 538 ...S3) can be helpful as interruptions caused by vibrations/oscillations are gener-
ally shorter than 70 ms.
The DDLS 538 ... S3 can be used to prevent the control from triggering any general EtherCAT Link down
within the 70 ms ("Operational" operating mode is deactivated).
To do this, adaptations must be made in the registry of the Beckhoff control system.
Ä In the control link mentioned below, the number of lost or defective protocols, above which deactivation
of the "Operational" operating mode occurs, must be changed.
Ä The number of missing, non-transmitted protocols must be configured based on the cycle time of the
control and the DDLS 538 ...S3 delay of 70 ms.
Example:
DDLS 538 delay time = 70 ms, cycle time of the Beckhoff control = 2 ms
EtherCATMaxMissingFrames = 70 ms / 2 ms = 35.
This means that the control deactivates the "Operational" operating mode only after 35 successive, non-
regularly transmitted protocols.
Link to the parameter in the Beckhoff control
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Beckhoff\TwinCAT3\Io]
"EtherCATMaxMissingFrames"=dword:00000020
Please contact Beckhoff technical support if you have further questions.
7.4.3

Calculation of the control cycle time

NOTICE
When installing an EtherCAT data transmission path, the calculated minimum control cycle time
must be adhered to.
Ä The actual control cycle time must be greater than or equal to the calculated minimum cycle
time.
Ä The DDLS 538 ... S2 and DDLS 538 ... S3 should not be used for control cycle times that
are shorter than the calculated minimum control cycle time.
Leuze electronic GmbH + Co. KG
DDLS 538 internal delay until
Phy shutdown
5 ms
70 ms
DDLS 538 ...
DDLS 538 restart after Phy
shutdown
~1.5 s
~1.5 s
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