Meaning
Time variances describe the deviation from the ideal arrival time of periodic messages across an industrial network. Excessive fieldbus jitter interferes with the synchronization of distributed control systems by introducing uncertainty into sensor readings. This phenomenon occurs due to network congestion or electromagnetic interference.
The variance is measured as the difference between the actual and the expected arrival time of a data packet. This measurement is necessary for identifying bottle necks in high speed data transmission.
Network Latency
Communication delays become problematic when they are not constant across all cycles. While a steady delay can be compensated for, fieldbus jitter creates a variable gap that prevents precise timing in high speed motion applications. This instability leads to vibrations in mechanical systems and errors in coordinated movement.
Operational Yield
Moving from a lab prototype to a full factory floor often exposes systems to higher levels of electrical noise. High fieldbus jitter during production runs can cause intermittent faults that are difficult to diagnose and fix. These faults reduce the overall yield by causing unexpected machine stoppages.
Signal Stability
Shielding and proper network topology reduce the impact of external interference on the data stream. When fieldbus jitter remains within defined limits, the control system can maintain the demonstrated rate of production without error. Exceeding these limits requires a reduction in communication speed or an upgrade to more robust physical media.
