Warehouse automation
SAP EWM MFS telegram problems: timeouts, retries, sequence gaps
MFS BlackBox reconstructs the telegram exchange between the Material Flow System and the PLCs from a telegram log and reports the first causal divergence and the anomalies around it.
Detected by:MFS BlackBox
Documented problems
- CriticalFirst causal divergence in the incident timeline
MFS_FIRST_CAUSAL_DIVERGENCE
- CriticalLIFE / heartbeat telegram gap exceeds the timeout
MFS_HEARTBEAT_TIMEOUT
- CriticalHU moved between non-adjacent conveyor points
MFS_IMPOSSIBLE_TOPOLOGY_JUMP
- CriticalTelegram not acknowledged within timeout
MFS_MISSING_ACK_TIMEOUT
- CriticalWarehouse task confirmed for a wrong HU / destination or twice
MFS_WRONG_CONFIRMATION
- MajorMalformed telegram record
MFS_CORRUPTED_TELEGRAM
- MajorDuplicate telegram retransmission (retry storm)
MFS_DUPLICATE_TELEGRAM_SEND
- MajorWarehouse task never confirmed
MFS_MISSING_COMPLETION
- MajorTelegram sequence out of order or with gaps
MFS_OUT_OF_ORDER_SEQUENCE
- MajorAnomaly rate increased after a PLC software release change
MFS_PLC_RELEASE_REGRESSION
- MajorIncident fingerprint recurs across HUs / occurrences
MFS_RECURRING_INCIDENT_PATTERN
Terms used in this area
Background articles
- SAP EWM Material Flow System (MFS): diagnosing PLC telegram errors and sequence gapsHow SAP Extended Warehouse Management communicates with programmable logic controllers (PLCs) over MFS telegrams, and how to diagnose handshake timeouts, sequence mismatches and channel resets.
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