I. Common Causes at the Physical Network Layer
A physical link interruption is the result of a damaged network cable, loose network interface, or RJ45 connector.
The MAC addresses of MES and SCADA were not properly learned, resulting in an industrial switch port failure.
The high packet loss rate is a result of the strong electromagnetic interference that occurs when power lines and communication network cables are laid in the same cable tray.
Network broadcast storms or loops, which obstruct the transmission of synchronisation data packets and saturate bandwidth.
II. Common Reasons at the Communication Protocol Layer
A disparity between the OPC UA/MQTT driver and the system firmware version; incompatible protocol versions at both ends.
The dedicated communication port for RC calibration data is being blocked by an industrial firewall; the port is not accessible.
The handshake connection was denied due to the inconsistency of security policies and encryption levels at both ends of the OPC UA protocol.
Communication IP address configuration conflict; SCADA and MES are not located on the same network segment.
III. Common Reasons at the Data Mapping Layer
The data parsing process is impeded by the misaligned RC parameter register addresses and point IDs on both sides.
Data distorted characters are the result of data format mismatches, inconsistent numerical types, units, and decimal places configurations.
Version discrepancies in pass thresholds and judgement rules exist on both sides of the RC calibration benchmark parameter versions, which are currently out of sync.
Data semantics are absent; data quality identifiers are not uniformly confined, which leads to unusable data following synchronisation.
IV. Common Reasons at the Service Operation Layer
The data acquisition service on the SCADA side and the synchronisation scheduling service on the MES side both experience crashes, resulting in their inability to function properly.
Synchronisation delays are the result of a severe message backlog in the message queue, which prevents the timely consumption of RC calibration data.
Synchronisation write timeout errors are the result of a slow query backlog and the exhaustion of the database connection pool.
Synchronisation tasks are unable to be scheduled or executed due to insufficient system resources; CPU and memory usage exceed 95%.
V. Common Causes at the Concurrency Timing Layer
The simultaneous upload of RC calibration data by multiple devices results in synchronisation request congestion and timing conflicts.
Excessive timestamp discrepancies between the two ends are the result of the absence of PTP/NTP unified time synchronisation, rendering data mismatches impossible during breakpoint resumption.
The priority of the synchronisation task is set to an insufficient level, which enables routine production data acquisition tasks to take precedence over system resources.
In scenarios involving high-frequency data acquisition, the absence of a change notification mechanism and an increased polling burden can result in synchronisation failures.
These reasons account for 99% of RC calibration data synchronisation failure scenarios and can be directly compared to rapidly identify the root cause.
