Deterministic Network Fabric

Control traffic rides a time-triggered network where every frame has a scheduled slot, so communication latency is bounded and jitter is negligible.

Why not standard Ethernet

Best-effort networking shares a medium by contention; under load, latency has a long tail. That is unacceptable for a control plane with a 10 µs deadline. Kronos runs control traffic on a time-triggered deterministic fabric where each critical message is assigned a fixed transmission slot on the shared clock, so its delivery time is scheduled rather than raced for.

Slotted schedule

The network's communication schedule is computed offline and loaded as a table. State-vector frames, setpoint frames, and gate signals each occupy known slots in a repeating cycle. Because two critical frames never share a slot, there is no queuing delay and no collision; end-to-end transport latency is a constant plus bounded skew.

Traffic classes

• Time-triggered: protection and fast-loop frames, hard-scheduled.
• Rate-constrained: telemetry to L2, bandwidth-limited but bounded.
• Best-effort: configuration and logging, only in unused slots.

Segregating classes ensures that non-critical traffic — pushing telemetry to the petabyte archive, loading a new bitstream — can never delay a protection frame. The best-effort class is literally confined to slots the critical schedule leaves free.

Determinism end to end

Combined with the shared clock, the fabric extends L1's timing guarantees across the whole machine: a sensor sampled on one node, processed on an FPGA on another, and acted on by a driver on a third all stay inside the composed timing budget. This is what lets both the breeder and burner control planes be physically distributed yet behave as one deterministic system.