Lenze 8400 TopLine - Manual (Page 846)

14 Axis bus
14.2 Data transfer axis bus
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Lenze · 8400 TopLine · Reference manual · DMS 6.0 EN · 06/2014 · TD05/TD14
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14.2.4.7 Axis bus data error monitoring
Operating mode
There are two error counters, one for incorrectly sent telegrams (
C02438/1 ) and one for incorrectly
received telegrams ( C02438/2 ).
• In an error-free normal operation, both error counters are = 0.
• Depending on the error type, the counters are increased by 8 in case of an error detection, and
reduced by 1 in case no error has occurred.
• If one of the two error counters is > 96, a warning is signalled via the LED AB-STATE (double
pulse).
• If an error counter increases or remains unchanged, a watchdog counter is increased in a 1-
ms cycle.
• If an error counter is reduced, the watchdog counter remains unchanged.
• If the error counters are = 0, the watchdog counter is reset to 0.
• If the watchdog counter reaches the monitoring time set in C02431/3 :
• The error response set in C00591/1 is activated (Lenze setting: "Fault").
• The error message " Ab01: AchsbusTimeOut " is entered into the logbook.
Parameterisation notes for "electrical shaft" application
When an "electrical shaft" is operated via an axis bus or generally via a bus system, data transfer
errors may occur due to e.g. EMC interferences. In order to prevent a mechanical offset of the drives
in case of a short-time interference only, the L_Interpolator_1 function block should be used in the
slave drives. This function block has an internal correction mechanism which provides for an
automatic offset correction in case of a missing data telegram. The error monitoring can then be set
to an insensitive value ( C02431/3 = approx. 10 ... 30 ms) which results in a very robust transfer
system.
What happens in case of a cable break, loose contact or short circuit of the axis bus cable?
Such severe errors mostly cause a bus-off error in one or even several devices of the system.
• In this case as well, the data error monitoring is triggered.
• The "BusOff" state will be automatically reset after the time set in
C02431/2 has expired if the
error cause has been removed. Then, the axis bus changes to normal operation again.